Hi, hope you find well.

A month ago,we face some trouble on our ESD F-AI module, it say that the module has a "ADC/DAC Faulty" shows on diagnostic buffer and has recommendation to "Replace the module".

The procedure we do is :

1. Open the IO front connector 
2. Loosen the bottom screw on the module
3. Unplugged module from rails
4. Setting the DIP Switch on the new module identical with the old one
5. Plug in the new module into the rails
6. tighten the bottom screw on the new module
7. plugin the IO front connector

The strange things happen when we unplugged the module from the rack. Every instrument value within the module was immediately derivation to approx -20% from its usual working value and sadly its generate a  trip.. 

The funny thing is we have done this procedure for a years, and this spurious thing have been given me a traumatic condition (lol) on how to replace the module when PLC/controller device system is still online.

Do you have any advice ? Or you guys have an experience regarding this issue ?

note:

• Our system was configured in redundancy setup both hardware and software. 
• CPU 417H (6ES7417-4HT14-0AB0)
• F-AI (6ES7336-4GE00-0AB0) installed in ET200M (6ES7153-2BA02-0XB0).

Hi Krist,

In practice it's never recommended to replace F-modules in running process because of the F-standards: Category 4 (EN 954-1)/ SIL3 (IEC61508)/PLE (ISO13849)

Check the URL for wiring the F-AI:

https://support.industry.siemens.com/cs/ww/en/view/24690377

Next if you have H-system then check in which OB's this Failsafe process is called and optimized.

Check the wiring specifications of 6ES7 331-1KF02-0AB0/ 6ES7 331-1KF00-0AB0 modules and it's multifunctional options. Link attached below

https://support.industry.siemens.com/cs/ww/en/view/8831413

https://support.industry.siemens.com/cs/ww/en/pv/6ES7331-1KF02-0AB0/td?dl=en

Regards

OmKris