Applies To:
  • CitectSCADA 5.xx, 6.xx
  • CitectHMI 5.xx, 6.xx
Summary:
CitectSCADA has an I/O Device configured to communicate to an OPC Server. The tags associated to the OPC I/O Device are reading the correct values until a write command is issued, following this tags read #COM instead of the correct values. Why is this happening?
 

Solution:
The issue may be experienced if the OPC server accepting Asynchronous writes. CitectSCADA's OPC driver only supports synchronous writes. A way to work around the issue is to configure the OPC server to accept synchronous writes. 
 
Keywords:
OPC, #COM  

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