Communication Hanging - S71200

All

We have 3 Nos. of S71200 System running  3 Different Machines

All  3 S71200 are connected through Wincc V8.0 Updade 4 through unmanaged Ethernet Switch

There is a frequent ( 2-3  times in a day ) communication failure Between 1 No.S71200 & Wincc 8.0 Up4

Once the communication failed, The communication between other controllers to Wincc also failed

We tried to Stop & Reactivate the Wincc, but still, tags are not communicating

Even if restarting the PC  the tags are  not fixing, then we have to power cycle the PLC to make it communicate again

We have checked all the Communication Cable Healthiness, Pinging is fine, In the Diagnostic Buffer No Error Code

The Firmware for CPU 1214-C is 4.6.1

Please let me know the reason for the Communication Hanging in the CPU / Wincc.

Awaiting for your valuable reply

Thanks & Regards

Iyyappan S

The way you describe the problem, it sounds like the CPUs saturate the number of possible connections, as if the connection drops much more frequently than of you see, but the expiration reestablishes it on a new PLC resource, until it saturates them waiting for the slow timeout, which you overcome by turning the PLC back on.

Since the problem is common to all CPUs, I would start by checking everything in common: replace the switch, the scada's network card, the PC station.

In the meantime, also try defining in the PLCs network configuration a scada station with a static IP address.

Thanks for the Reply

Please let me know that whether we need to do any Setting in S71214C CPU Properties in TIA