# OpcClient.SubscribeDataChange Method > Reference: Subscribes data changes on the Value attribute of the node specified by nodeId.
Type
OpcClient
Namespace
Opc.UaFx.Client
Assembly
Opc.UaFx.Advanced.dll
Package
Opc.UaFx.Advanced v2.59.0
Members
OpcClient Members
Also in
Opc.UaFx.Client
66 overloads | Overload | Description | |---|---| | [SubscribeDataChange(byte\[\], OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(Guid, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(int, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(uint, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(string, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(byte\[\], OpcAttribute, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(Guid, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(int, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(uint, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(string, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(byte\[\], int, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-system-int32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | [SubscribeDataChange(Guid, int, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-system-int32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | [SubscribeDataChange(int, int, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-system-int32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | [SubscribeDataChange(uint, int, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-system-int32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | [SubscribeDataChange(string, int, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-system-int32-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | [SubscribeDataChange(byte\[\], int, OpcAttribute, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-system-int32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`. | | [SubscribeDataChange(Guid, int, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-system-int32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`. | | [SubscribeDataChange(int, int, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-system-int32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`. | | [SubscribeDataChange(uint, int, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-system-int32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`. | | [SubscribeDataChange(string, int, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-system-int32-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`. | | [SubscribeDataChange(byte\[\], OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(byte\[\], OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(Guid, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(Guid, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(uint, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(uint, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(string, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(string, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(byte\[\], int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-system-int32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(byte\[\], int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-system-int32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(Guid, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-system-int32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(Guid, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-system-int32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(int, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-system-int32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(int, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-system-int32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(uint, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-system-int32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(uint, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-system-int32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(string, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-system-int32-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(string, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-system-int32-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(byte\[\], OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(byte\[\], OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(Guid, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(Guid, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(uint, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(uint, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(string, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(string, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(byte\[\], int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(byte\[\], int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](#subscribedatachange-system-byte-array-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(Guid, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(Guid, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-guid-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(int, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(int, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-int32-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(uint, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(uint, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-uint32-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(string, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(string, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-system-string-system-int32-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified. | | [SubscribeDataChange(OpcNodeId, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-opc-uafx-opcnodeid-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(OpcNodeId, OpcAttribute, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-opc-uafx-opcnodeid-opc-uafx-opcattribute-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(OpcNodeId, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-opc-uafx-opcnodeid-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(OpcNodeId, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-opc-uafx-opcnodeid-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`. | | [SubscribeDataChange(OpcNodeId, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-opc-uafx-opcnodeid-opc-uafx-opcattribute-opc-uafx-opcdatachangefilter-opc-uafx-client-opcdatachangereceivedeventhandler) | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | | [SubscribeDataChange(OpcNodeId, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcclient/subscribedatachange#subscribedatachange-opc-uafx-opcnodeid-opc-uafx-opcattribute-opc-uafx-opcdatachangetrigger-opc-uafx-client-opcdatachangereceivedeventhandler)since v2.6 | Subscribes data changes on the `attribute` of the node specified by `nodeId`. | **Exceptions (all overloads)** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The `nodeId` is empty. | | [InvalidOperationException](https://learn.microsoft.com/dotnet/api/system.invalidoperationexception) | The subscription service is currently not supported, especially using the arguments specified. | | [ObjectDisposedException](https://learn.microsoft.com/dotnet/api/system.objectdisposedexception) | The object has been disposed of. | | [OpcException](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcexception/) | The service execution failed upon different circumstances; for more details see exception details. The following issues can lead to that exception: [BadNothingToDo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badnothingtodo), [BadTooManyOperations](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badtoomanyoperations), [BadTimestampsToReturnInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badtimestampstoreturninvalid), [BadSubscriptionIdInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badsubscriptionidinvalid), [BadMonitoringModeInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badmonitoringmodeinvalid), [BadNodeIdInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badnodeidinvalid), [BadNodeIdUnknown](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badnodeidunknown), [BadAttributeInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badattributeinvalid), [BadIndexRangeInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badindexrangeinvalid), [BadIndexRangeNoData](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badindexrangenodata), [BadDataEncodingInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#baddataencodinginvalid), [BadDataEncodingUnsupported](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#baddataencodingunsupported), [BadMonitoredItemFilterInvalid](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badmonitoreditemfilterinvalid), [BadMonitoredItemFilterUnsupported](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badmonitoreditemfilterunsupported), [BadFilterNotAllowed](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badfilternotallowed), [BadTooManySubscriptions](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badtoomanysubscriptions) and [BadTooManyMonitoredItems](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/#badtoomanymonitoreditems). | ## SubscribeDataChange(byte\[\], OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], int, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, int namespaceIndex, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), namespaceIndex As Integer, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, int, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, int namespaceIndex, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, namespaceIndex As Integer, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, int, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, int namespaceIndex, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, namespaceIndex As Integer, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, int, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, int namespaceIndex, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, namespaceIndex As Integer, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, int, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified to operate on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, int namespaceIndex, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, namespaceIndex As Integer, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], int, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), namespaceIndex As Integer, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, int, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, namespaceIndex As Integer, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, int, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, namespaceIndex As Integer, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, int, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, namespaceIndex As Integer, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, int, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified to operate on the `attribute`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, namespaceIndex As Integer, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, int namespaceIndex, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), namespaceIndex As Integer, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, int namespaceIndex, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), namespaceIndex As Integer, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, int namespaceIndex, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, namespaceIndex As Integer, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, int namespaceIndex, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, namespaceIndex As Integer, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, int namespaceIndex, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, namespaceIndex As Integer, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, int namespaceIndex, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, namespaceIndex As Integer, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, int namespaceIndex, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, namespaceIndex As Integer, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, int namespaceIndex, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, namespaceIndex As Integer, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, int, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, int namespaceIndex, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, namespaceIndex As Integer, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, int, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, int namespaceIndex, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, namespaceIndex As Integer, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), namespaceIndex As Integer, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(byte\[\], int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( byte[] nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Byte(), namespaceIndex As Integer, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Byte](https://learn.microsoft.com/dotnet/api/system.byte)[] | The opaque node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, namespaceIndex As Integer, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(Guid, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( Guid nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Guid, namespaceIndex As Integer, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Guid](https://learn.microsoft.com/dotnet/api/system.guid) | The general unique identifier (= GUID) of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, namespaceIndex As Integer, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(int, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( int nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As Integer, namespaceIndex As Integer, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, namespaceIndex As Integer, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(uint, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( uint nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As UInteger, namespaceIndex As Integer, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [UInt32](https://learn.microsoft.com/dotnet/api/system.uint32) | The numeric node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, int, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, namespaceIndex As Integer, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(string, int, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId` and `namespaceIndex` specified.
```csharp public OpcSubscription SubscribeDataChange( string nodeId, int namespaceIndex, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As String, namespaceIndex As Integer, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The textual node identifier of the node to subscribe. | | `namespaceIndex` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The index of the namespace within that the node with the `nodeId` specified can be located. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. ## SubscribeDataChange(OpcNodeId, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( OpcNodeId nodeId, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As OpcNodeId, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the node on which the service, who will execute this command, will operate on its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). | ## SubscribeDataChange(OpcNodeId, OpcAttribute, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( OpcNodeId nodeId, OpcAttribute attribute, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As OpcNodeId, attribute As OpcAttribute, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the node on which the service, who will execute this command, will operate on its `attribute`. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). | ## SubscribeDataChange(OpcNodeId, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( OpcNodeId nodeId, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As OpcNodeId, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the node on which the service, who will execute this command, will operate on its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). | ## SubscribeDataChange(OpcNodeId, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( OpcNodeId nodeId, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As OpcNodeId, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the node on which the service, who will execute this command, will operate on its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#value) attribute. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). | ## SubscribeDataChange(OpcNodeId, OpcAttribute, OpcDataChangeFilter, OpcDataChangeReceivedEventHandler) Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( OpcNodeId nodeId, OpcAttribute attribute, OpcDataChangeFilter filter, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As OpcNodeId, attribute As OpcAttribute, filter As OpcDataChangeFilter, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the node on which the service, who will execute this command, will operate on its `attribute`. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `filter` | [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) | The [OpcDataChangeFilter](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangefilter/) to be used by the server's subscription to - which the monitored item belongs - to filter the monitored data before it is reported to the client, which owns the monitored item. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). | ## SubscribeDataChange(OpcNodeId, OpcAttribute, OpcDataChangeTrigger, OpcDataChangeReceivedEventHandler) since v2.6 Subscribes data changes on the `attribute` of the node specified by `nodeId`.
```csharp public OpcSubscription SubscribeDataChange( OpcNodeId nodeId, OpcAttribute attribute, OpcDataChangeTrigger trigger, OpcDataChangeReceivedEventHandler received) ```
```vbnet Public Function SubscribeDataChange( nodeId As OpcNodeId, attribute As OpcAttribute, trigger As OpcDataChangeTrigger, received As OpcDataChangeReceivedEventHandler) As OpcSubscription ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the node on which the service, who will execute this command, will operate on its `attribute`. | | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration that defines which node attribute is to be used by the subscription. | | `trigger` | [OpcDataChangeTrigger](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangetrigger/) | The conditions used by the server under which a data change is to be reported. | | `received` | [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) | The [OpcDataChangeReceivedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcdatachangereceivedeventhandler/) method to assign as the event handler of the [DataChangeReceived](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/members#datachangereceived) event or a null reference (Nothing in Visual Basic) if there no event handler is to be assigned first. | **Returns** [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) A new instance of the [OpcSubscription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcsubscription/) class with a single [OpcMonitoredItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.client.opcmonitoreditem/) setup with the information specified. The kind of monitored item will when monitor data changes performed on the node identified by the values passed to this method. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). |