System Fault (SF) while executing Analog Inputs

I am using a  S7-300 PLC ,CPU313C ,part no: 6ES7 313-5BG04-0AB0 , suddenly i am getting a issue whenever i connect my Analog device (say a potmeter) in my AI0 terminal with the address PIW2 and putting the plc to RUN mode ,the SYSTEM FAULT (SF) Led is getting enabled .

The program is not getting executed . I have checked the connections but everything is fine .

What maybe the solution to get back my AI/AO's function back to normal . I have my VFD SINAMICS V20 in standstill for execution till the SF Error is rectified. 

Kindly suggest !! 

hi maahi,

share the diagnostic buffer of the CPU with us. export it as txt-file and attach it here.

regards

Thank you for your prompt response .

Kindly find the attachment .

Hi, 

The code try to access an IO what is not available. When you are online with CPU in the diag buffer, you click on the "go to" button and it will bring you to the place of the problem.  Than you can find out if it is and addressing error in the code or the IO is not responding.

The other thing is the OB122. Make sure you have the fault obs loaded to keep your PLC going. See the Which organization blocks do you need for error handling in STEP 7 V5.5?