Hello everybody,

I'm using a Siemens 1512SP PLC with a TURK BLCEN-2M12MT RFID module communicating via Profinet IO.

The system usually works fine, but sometimes, completely randomly the PLC shows profinet error and than it stops. Therefore I monitored the Profinet communication between the PLC and the BLECN. What I found that, normally the PLC sends something and than there is a response from the Rfid module. In a moment then, the BLCEN sends three messages, and the PLC as well. After the fourth time the PLC sends an alarm to the Rfid module.

I attached a picture about the wireshark capture and about the Profinet settings.

Any ideas what could be the problem?

Thank you,

Gergö

Hello,

in my opinion some defined maximal timeout of receive from Turck has expired. Looks like messages are ok in my opinion.

Update: you accept 3 messages without I/O data, so that watch Dog Timeout 6 ms point also to that. try bypass/test this situation maybe with more accepted messages value without I/O data, also if it is accepted to you.

Dear Duris,

Thank you for you message! I was trying manny different settings however the problem happens so often (once a day or once in two days) that I had no luck with "try and error" method.

Can you please explain or send any datasheet about what is the right method to set up the IO cycle update time and watchdog time settings?

Thank you,

Gergö

Hello,

Refer the SIMATIC PROFINET  with STEP 7 V14 manual having chapter 2.1 page number 22.

https://support.industry.siemens.com/cs/in/en/view/49948856

Dear DJ,

Thank you for the documentation!

However I didn't find anything what could be the problem.

hi,

you wrote, that the CPU stops. Can you share the diagnosic buffer with us?

regards,

Dear mop S04,

unfortunatelly the system is not available for me anymore. However in the following situation I will save that in case it might help!