Recently, one of my colleague has faced the problem that during running of system in normal condition, someone has pullout the failsafe module which triggered the ET200M failure.
As per our discussion few things came into the picture, that are showing as below:
1. Hot swapping is allowed only with Active bus modules.
2. Hot swapping is allowed only with S7-400 or S7-400H CPU or it’s successor.in S7-300 CPU further settings required.
3.Most important point to consider is that OB83 should be engineered within the program to prevent STOP mode when remove module from rack.
4. PCS7 has CIR functionality which can be enable for hot swapping and future expansion.
5. In case of Failsafe module, isolater should never been removed from the rack as it may result of ET200M rack failure.
Attention point:
1. Check that available ET200M and modules supports HOT SWAPPING or not. To see if your module supports this function, please consult the STEP 7 hardware configuration ( select the module in the catalog > the lower dialog box displays the support modules in plaintext) or in chapter 9 of the manual “SIMATIC Distributed Peripheral Deviced ET 200M”.
2. A requirement for this function is the use of an active backpanel bus. The conventional bus connectors (U piece) do not support this function since the backpanel bus is disconnected during the removal of a module.
3. Furthermore, you need at least a IM153-1 with the MLFB 6ES7 153-1AA02-0XB0.
Older modules, for example modules with the MLFB IM153-1AA00-0XB0 do not support this function.
Please refer below showing link for more details:
hot swapping of signal module