Dialog 11 hangs after CMOS CHECKSUM OK

When transferring a program to my FP4-60T (dialog 11) today, the transfer suddenly stopt .
After I aborted the transmission, with intentions of trying it again, the control froze and didn’t respond to any key anymore.
So, I shut down the control and switched both of the main switches off.
When rebooting, all checks in the selftest are checked and okay, but after that the control hangs and displays the following message: CMOS CHECKSUM OK.

On the NSV, F2 is shown on the 7-segment displays.

Also none of the LED's on the NPC are turned on. When I reboot again and press the reset button on the NPC, the run LED turns on, but the control still hangs with the same message displayed.

Does anybody have a list with NSV error codes or know's how to solve the problem? I do have the orange book, but there is nothing in it about the Grundig SPS (PLC) unit, only about the machine and the Bosch drives.

Don’t know what the F2 code means and if it normally appears when the machine is working fine.
I believe when rebooting that FF is shown briefly.

It’s a bummer because I was just working on a few parts for a new customer…

Thanks, Paul

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