I have customer that purchase spare parts in the box there Alert about internal Battery Backup functionality.
"Without the"hold acknowledge" modification the...."
PM803F with a serial number >637 should be used only together with modified EI 81xF and AM 811E. Without the hold acknowledge" modification the Ethenet communication may get faulty.
Modules with the specific hardware inder have to be modified befoe usage.
The note above is part of the Alert. Can this be explained? Can the modification be provided?
One issue is the battery backup functionality which for this new CPU is not given with EI 80XF (X being 1,2 or 3) or AM 801F. Use EI 81XF or AM 811F with hardware index 2.00 or higher instead.
There is also a communication issue which requires a "hold acknowledge" modification to be made. The hardware indexes that need modification are given in the table. If you have an EI 81X with a higher hardware index than those given in the table, no change is needed. If changes are needed they can be provided by the repair shop in Ratingen, Germany.
I guess, that if the modules are in warranty the changes are made without charging you. But you should verify that with the workshop.