Applies To:
  • CitectSCADA

I have a test project in Citect connected to an Allen Bradley SLC505 via TCP/IP.

The communications interface looks to be configured ok.

If I set a bit in the PLC from the programming interface Citect immediately displays its value.

In the kernel you can see a steady increase in the comms error count as you try to write to the PLC from Citect.

What is the problem?


The communications configuration in Citect looks correct. (In fact it is.)

Within the SLC505 setup there is the facility to "Write Protect" a communications channel.

This is set once only on setup of the PLC and once set will prevent Citect writing to the PLC via the comms channel.