maoravni - 2021-10-17

I have a PLC with very strange PLC Load behavior.

The project is running fine with all libraries upgraded to latest SP 17, except for TCP network traffic.

TCP packets take forever to read and write - we've seen response times of 40 seconds.

When checking the PLC load we see that the load is unusually high at ~60%.

Checking the task monitor we don't see anything out of the ordinary - the background task where all of the communication is performed is taking ~1000us average cycle time. Max cycle time is ~1600us.

When switching the network library back to version SP 6, where it originally worked, the TCP stack functions as expected.

When checking the PLC load we see the expected load - ~10-15%, and the background task takes up ~3000us.

This is the same project, with only the version of the network library changed.

Did anyone encounter this? Any pointes?

Thanks,
Maor