PROFINET Communication Error

Hi,

I am struggling with problem of loss of Profinet communication in system with CPU 1513-1 PN (whole topology in attachment). 4-5 times a day in different hours communication breaks down which causes disconnecting all devices. After a while communication is back again, but all V90 drives after error have to be calibrated, which is the biggest problem cause it stops the proccess. Usually as a first error in diagnostic buffer appears „Error on partner – IRT not possible at this port” .Error relates to CPU, first or second drive V90 in topology. After this error, in buffer appears „Communication to device logical address … faulty. Signs of life of drive faulty” on all drives. Whole diagnostic buffer is in attachment.

Topology correctly represents physical connections. Network was also checked with analyser but no anomalies were found.

Hardware:

- shielded Profinet cables with connectors from Siemens

- all V90 drives connected in series in one cabinet

- CPU: 6ES7 513-1AL02-0AB0

- V90: 6SL3 210-5FE11-5UF0 oraz 6SL3 210-5FE12-0UF0

Did anyone have similar problem or maybe anyone knows potential solution?

I increased the time to 32ms and error appeared after 20 hours. Maybe it helped with frequency of errors but problem still exists. 

Do you have any other ideas?

This may be an EMC issue?

Pre formed motor cables; if these are not being used, look at the screen connections at the motor end and the drive end, and any cable breaks in between.

Tractor

I have used original Siemens motor cables between V90's and Siemens motors. Also didn't find any breaks or damages of cables. So i doubt if physical connection may be the reason.

I didn't mention earlier that in the Profinet network there is also one device that uses Modbus TCP (Safety PLC from Pilz). Is it possible that it disrupts IRT communication between V90's and S7-1500?

In the IRT configuration, how is the profinet update time allocated?  Balanced, more towards cyclic?  How much of the PN clock is allocated to the IRT traffic?  How long is allocated for it?

When the MB/TCP is trying to send, is the OB handling the MB/TCP send/receive getting updated using a cyclic interrupt OB with an offset longer than the IRT max traffic allocation so they are not trying to start at the same time?

mick1211

I have used original Siemens motor cables between V90's and Siemens motors. Also didn't find any breaks or damages of cables. So i doubt if physical connection may be the reason.

I didn't mention earlier that in the Profinet network there is also one device that uses Modbus TCP (Safety PLC from Pilz). Is it possible that it disrupts IRT communication between V90's and S7-1500?

Hi,

@0_Einstein Could you tell me more specifically which parameters should I check?

IRT comunication is handling by OB Servo with time 32 ms, Modbus comunication is handled by OB1, we could move it to some cyclical OB (e.g. with time 100 or 200 ms).

AdditionaIly i have replaced Profinet switch and after that Communication Errors became only Warnings.