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7:16, EEST
September 4, 2012
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Hi !
When then client write a value to “My.OPC” Server, how to know?
I don’t want “TPsVars.OnChange”, because I don’t know how determine it’s the sever self write or the client write.
From the client write to server, server must be write to PLC, have another solution.
Best regards
10:35, EEST
December 21, 2011
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It is currently not possible to tell where the change is coming from.
In principle, you should write the “server changes” using SetPropValueAt, which “forces” the change into the variable. The “client writes” use PropValue-property. However, they both trigger OnChanging and OnChange, so you cannot tell which one was called at that point.
The only solution is to mark the variable, for example, using the Tag property before you are writing “server changes” and check the value of Tag in OnChanging or OnChange.
In OnChanging you can reject the change as well, in which case it will not be written to the variable at all. Except when SetPropValueAt is used, in which case the result of OnChanging is ignored.
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