Dear All, 

              Anyone know why system error came in CPU551 and how to avoid this issue. 

For reference attachment is also shared. 

miami

You have to read the diagnostic buffer of CPU (s) . Go online with SIMATIC Manager.

If one "H" is flashing, this CPU has detected a fault, it's diagnostic buffer is the interesting.

 Please describe in brief where I check the buffer?  

KSN

Hello.

Connect locally to the CPU via DUST1. Go to the CFC-menu 'CPU-Module Information'. There will appear the window with 2 tabs ('Error fields' and 'Exception buffer'). Copy the contents of both tabs and contact Siemens with this error information.

 Sir 2 question comes into my mind:-

1. We have connection with LAN, should I check via LAN. 

2. When we check "if problem was in CPU or anytime?"

KSN

1. You can try to connect via LAN, but in most cases when the 'H'-fault occur all the interfaces except DUST1 don't work.

2. You should connect and read the errors when the fault is active.

 Thanks for your help sir. 

KSN

1. You can try to connect via LAN, but in most cases when the 'H'-fault occur all the interfaces except DUST1 don't work.

2. You should connect and read the errors when the fault is active.

 Sir I had checked in exception buffer, found some of the data. Please check and revert what was the actual cause. 

KSN

You should contact to Siemens Support with this info.

 Thanks for the suggestion sir. 

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