Q4115 Citect OPC Client connecting to Citect OPC Server, on startup the Citect OPC Client most values display "0.00" or "OFF" even though other OPC Clients display the correct value.

ArticleID: Q4115
Created: 5/07/2005
Last Updated: 23/11/2007
Suggested By: Olivier Vallee

Applies To:

CitectSCADA 5.xx, 6.00 CitectHMI 5.xx, 6.00

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Summary:

A Citect OPC Client is setup to connect to a Citect OPC Server. After startup of the Citect OPC Client most values display "0.00"or "OFF". It is only until the value is written to from the Citect OPC Client that the values begin to display correctly. Are there any special Citect.ini parameters required to get this working?

Solution:

The problem described is a bug in the Citect OPC component. When the Citect OPC server receives a IOPCAsyncIO::Refresh() request it always returns a OPCTMFORMATDATA format regardless of the data stream format expected by the Client. This problem has been resolved in a new build of the Citect OPC Server. Please contact Citect Support for the updated Citect OPC Server.

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Keywords:

OPC, OnDataChange, static, data, display