# OpcHistoryValue Class

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx">Opc.UaFx</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
<dt>Members</dt>
<dd><a href="./members">OpcHistoryValue Members</a></dd>
<dt>Also in</dt>
<dd>Opc.UaFx.Client</dd>
</dl>

Represents a value of the history of a node.

## Syntax

<div class="api-signature" data-lang="csharp">

```csharp
public class OpcHistoryValue : OpcValue
```

</div>

<div class="api-signature" data-lang="vbnet">

```vbnet
Public Class OpcHistoryValue
    Inherits OpcValue
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [OpcValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvalue/) → **OpcHistoryValue**

## Implements

<ul class="api-implements">
<li><a href="https://learn.microsoft.com/dotnet/api/system.icomparable">IComparable</a></li>
<li><a href="https://learn.microsoft.com/dotnet/api/system.icomparable-1">IComparable</a>&lt;<a href="../opc.uafx.opcvalue/">OpcValue</a>&gt;</li>
<li><a href="https://learn.microsoft.com/dotnet/api/system.iequatable-1">IEquatable</a>&lt;<a href="../opc.uafx.opcvalue/">OpcValue</a>&gt;</li>
<li><a href="https://learn.microsoft.com/dotnet/api/system.iformattable">IFormattable</a></li>
</ul>

## Derived types

- [OpcModifiedHistoryValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodifiedhistoryvalue/)

## Constructors

| Name | Description |
|---|---|
| [OpcHistoryValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#opchistoryvalue)<span class="api-meta">3 overloads</span> | Initializes a new instance of the OpcHistoryValue class using the `value` and `timestamp` specified. |

## Properties

| Name | Description |
|---|---|
| [Timestamp](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#timestamp)<span class="api-meta">virtual</span> | Gets the time of the value, by which the history is ordered. |

## Methods

| Name | Description |
|---|---|
| [CompareTo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#compareto) | Compares the current OpcHistoryValue with another OpcHistoryValue. |
| [Create](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#create)<span class="api-meta">static · 2 overloads</span> | Creates an OpcHistoryValue from the `value` specified. |
| [CreateModified](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#createmodified)<span class="api-meta">6 overloads</span> | Creates an [OpcModifiedHistoryValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodifiedhistoryvalue/) from this value using a modification of the `modificationType` specified at the current time (UTC). |
| [Equals](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#equals)<span class="api-meta">2 overloads</span> | Determines whether the specified `other` is equal to this OpcHistoryValue. |
| [GetHashCode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#gethashcode)<span class="api-meta">override</span> | Retrieves a hash code for this OpcHistoryValue. |
| [ToString](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#tostring)<span class="api-meta">override · 2 overloads</span> | Returns a string that represents the history value. |

## Operators

| Name | Description |
|---|---|
| [Equality](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#op-equality)<span class="api-meta">static</span> | Returns a value indicating whether two instance of OpcHistoryValue are equal. |
| [GreaterThan](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#op-greaterthan)<span class="api-meta">static</span> | Determines whether the first specified OpcHistoryValue object is greater than the second specified OpcHistoryValue object. |
| [GreaterThanOrEqual](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#op-greaterthanorequal)<span class="api-meta">static</span> | Determines whether the first specified OpcHistoryValue object is greater than or equal to the second specified OpcHistoryValue object. |
| [Inequality](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#op-inequality)<span class="api-meta">static</span> | Returns a value indicating whether two instances of OpcHistoryValue are not equal. |
| [LessThan](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#op-lessthan)<span class="api-meta">static</span> | Determines whether the first specified OpcHistoryValue object is less than the second specified OpcHistoryValue object. |
| [LessThanOrEqual](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryvalue/members#op-lessthanorequal)<span class="api-meta">static</span> | Determines whether the first specified OpcHistoryValue object is less than or equal to the second OpcHistoryValue object. |

Inherits members from [OpcValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvalue/members).

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.5–v2.59 |