A customer has a C70 PLC connected to six 483 PLCs via a Spider 8TX unmanaged switch. The setup used to be able to pass PLC data in both directions previously. After a minor code change, which has NOTHING TO DO WITH OPCUA configuration the communication has stopped working in one direction, i.e. the C70 is able to read the data from the 483s but the 483s do not, in fact the ‘Module-OK’ signal from C70 is read in the 483 as False even though the C70 is working fine. Any ideas why this could be happening?
I have checked out the network on UaExpert and it sees all the data that is configured on all sides. The setup uses a Spider 8TX unmanaged switch to network and it is not connected to anything else but these 7 units. Lastly, the original PLC program on the 483’s was built on Automation Studio 4.4.6 while I have used 4.4.4. I do not have 4.4.6 version, so even when I installed the previous programs the communication failuire continued exactly and with my code changes. Could going backwards on version cause such a problem?
Changing the Automation Studio version from 4.4.6 to 4.4.4 does not result in any traceable changes to OPC communication and should therefore not affect OPC communication.
But there is nothing stopping you from testing 4.4.6 as you can download the version here:
There were numerous improvements between the AR versions that came with AS 4.4 and the current AS4.12 AR versions. If this problem still exists, I suggest testing with the current AR versions 4.93.
I would also bet that problem is related to somewhere else, not to change of AS. But if the only difference is really used version of AS. Then record Wireshark trace and contact your local B&R office, support will help you to analyze it.
Thanks for your support. I upgraded the AS and runtime versions, and it all worked like magic. But the damage is done, I think this service call has caused me deep PTSD
thanks for feedback