Applies To:
  • CitectSCADA 5.xx

Can Citect communicate to the older Siemens CP535 card? 

You can use the S7-OPC server from Siemens. It is available free of charge on the Siemens Simatic Net May 2000 CD. This OPC server comes with a SEND-RECEIVE interface, which is what can be used to connect to the CP535 card. The SEND-RECEIVE interface will not allow reads and writes to the same job, so two jobs were set up in the OPC server and the CP535 card; one for SEND and one for RECEIVE. This also meant that if I wanted to read and write to the same address in the PLC, I had to define two tags, one referencing the SEND job, and a second referencing the RECEIVE job. In the Citect OPC client, you will need to configure 2 devices (one for the read only (RECEIVE) tags and the other for the write only (SEND) tags).