Hi,

Missing fault OB.

414-5H Linkup/Update - Reserve CPU Stops in the case of Power Off on the Master

I hope I could help!

When using redundand H system there are a number of error OBs that are required, even if you do not use them.

You can find them in the manual:

https://support.industry.siemens.com/cs/ww/en/view/82478488

They are listed in:

15.1 Configuring with STEP 7
....
Always download these error OBs to the S7-400H CPU: OB 70, OB 72, OB 80, OB 82, OB 83, OB 85, OB 86, OB 87, OB 88, OB 121 and OB 122. If you do not download these OBs, the fault-tolerant system goes into STOP when an error occurs.