AdsSymbolicServerHasValueChanged Method

Determines whether the value of the Symbol has changed.

Namespace: TwinCAT.Ads.Server
Assembly: TwinCAT.Ads.SymbolicServer (in TwinCAT.Ads.SymbolicServer.dll) Version: 7.0.0+e56d35ccc4675faac24789a4aab60071fc61d470

Syntax

C#

protected virtual bool HasValueChanged(
    ISymbol symbol
)

Parameters

symbol ISymbol

The symbol.

Return Value

Boolean
true if the value has changed; otherwise, false.

Remarks

This Method is used internally to find out, if a symbol was changed since the last notification trigger. Collecting Notifications and send them in cycles enforces that the information about changed values is cached somehow. In the case of the AdsSymbolicServer Symbols with outstanding notifications will have a flag in the internal notification tables.

Reference

AdsSymbolicServer Class TwinCAT.Ads.Server Namespace

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