I am using the matrikon opc odbc client to talk to a Modicon OPC server (factory server (OFS)). My problem is that if the Matrikon client is that when the matrikon client is restarted and comes on line, I may have PLCs that are no powered up. In this case the OFS cannot validate the item on its end and so the item is never created on the client side. Once this happens any communication to the PLC from the client is lost, even if it is subsequently powered up. I need for items to be validated on the Modicon side (againest the pre loaded symbol files?) so that they are created on the client side and available if the PLC comes back on line.

 

Your issue is likely due to the OFS server not having the item validated. My bet is that you're using the Modicon OPC server in a telemetry SCADA situation. Is this true? Without knowing anything else about your situation, my bet is that the server is failing because it wasn't designed for telemetry SCADA. I personally tried OFS and got the same results with my HMI. I had to switch to another server that took care of my telemetry needs.

Jimmy Maxwell