Hi all,

I have a problem with a CPU317-2 PN/DP, it is a running system for may years. just recently i have been able to ping the CPU, with a very show reponse time of 2-5mS, i can also see all the data on the PLC via a kepware OPC server.

My problem is when i try and go online with the my laptop ethernet connection using Step 7 Ver5.6 which i have used with this PLC/connection for a long time i get a very slow connection time and everntually i get an error message saying:- Online connection could not be established.The connection partner is not responding. Hardware diagnostics error 33:16656.

I have checked the network connections, i have tried to connect to the CPU directly, with all external ethernet connections removed just incase there was a network error, with no joy.

I can connect to the CPU using a MPI connection but i cannot find any errors on the CPU or modules. The only thing i can see is the MMC memory is at 98% of memory card capacity. would increasing the memory card size resolve this problem. Any help would be gratefully received.

Many thanks 

Ian

Hello IanEng

do you see any errors in diagnostic buffer?

CHeck the cycle times perhaps the PLC is running in stress.

Check the communication ressources in online view

Which Firmwareversion do you use?

Bye Murof

Good afternoon,

I do not have the same IP address on the network, my laptop IP address has not changed, i can ping the PLC ip address and i get a rapid response. I power down the PLC and i do not get a ping response so i know there is only one PLC with this ip address on my OT network.

Thank for your response

Hello,

I can only randomly access the hardware diagnostics, i cannot see any confliclt or error in the buffer, the only thing that is worrying me is the load memory (MMC) is at 97% capacity. I have read somewhere that if the memory is this full i can affect communications.

Thank you for your answer

Good afternoon,

I have managed to access the hardware buffer and this is the error test i am seeing, please see attached text file