S7-300 CPU goes to stop mode.

r.ethernet

Hi
While trying to figure out the problem of slave no.8 you can download mentioned OB(86) into cpu to prevent  stop mode!

 Sorry for the late response. Actually, the issues still exist in the CPU. Many of here suggested to download OB86 in the CPU but when i planning to do this, i see the OB86 already exists there. Please see the below attachments related to the OB86

Hello,

maybe in case of some Program problem you can download also OB122 and check if your STOP problem can be solved. Of course, also basic problem need to be investigate and solved.

OB122 also exit. If i call the FC71 by OB1 and keep the OB86 clean then can be help?

Hello,

it depends what problem occur. In other case, also of real Programm error detection you can also include OB121.

Update: look to complete CPU diagnostics, also check if basically also Scan Time of CPU doesn't exceed max. approved value.

If you don't use OB122 in any case one remote loses communication plc goes always stop mode and show alarm SF or BF.

Another case is if you use OB122 and lose communication plc LED SF BF flashing but didn't go stop mode. So you should use the OB86 block.