I am new to whole world of PLC programming and Industrial application.

Recently I have using a TIA V17 PLC application for testing a vendors Profinet firmware. I noticed 2 different behaviour.

Scenario : A batch of 32 drives are connected in Daisy Chain network with I/O cycle set as 1 ms using 1500 PLC. When all drives came online – we disconnected any drive say 7^thin sequence and observed that drives 1-6 at random showed flickering “Fieldbus Warning” warnings / connect – PLC connect / disconnect messages. Note that we have set Watchdog timer 3ms for all drives.

We observed that when we remove the cables connection as in [New Topology Changes View.png]  wrt old Topology [Old Topology View] in Topology view of PLC program having 1ms I/O connection and 3ms Watch Dog timer – the issue in concern does not occur.

Why do we see such a difference in between two different topologies - do we need to correct some config in [Old Topology View]?

Is it a PLC Application issue or issue with the Firmware? 

Closed cause question posted twice.

The second thread with the subject TIA V17 PLC Application Topology View is published within the conference Communication / Networks.