Archived:LabVIEW OPC I/O Client does not Read/Write to OPC Server in Simulation Mode

Updated May 4, 2021

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Reported In

Software

  • OPC Servers

Issue Details

I created a device in NI OPC Server and set the Simulate Device option as seen below:

Figure 1. Simulate device in OPC Server
When I create an OPC I/O client in my LabVIEW application and attempt to read or write to a shared variable bound to a tag from this OPC server, the appropriate value is not read or written when viewed in the Quick Client. However, the values are read and written to the shared variable when viewed in Distributed Shared Manager. Why can I not see my values in Quick Client?
 

Solution

This behavior is expected. When a value is written to a device in NI OPC Server that is simulated, it simply verifies communication and does not save the value on the server. This is the case for any client, LabVIEW or Quick Client.