GE Fanuc Nano Serial Communication?

I am trying to use the serial port on a GE Fanuc VersaMax Nano to communicate serially. Using the COMMREQ command I can change to serial (RS-232) mode when I am in run mode and the PLC automatically switches back to SNP mode when the the PLC is switched to stop. At this time I can reconnect my programming PC to the PLC.

But if I try changing the serial port settings, like baud rate or parity, when I switch back to run mode, I am unable to connect the programming PC to the PLC.

I also tried saving everything to flash memory and now the PLC is in some indeterminant state where I am unable to connect to it at all with the programming PC.

Is there some way to erase flash memory on the VersaMax Nano? How do I handle serial communications so that I can change the baud rate and parity in the ladder program while running but still allow the port to switch back to default SNP when stopped?

Joel

For changing back to default baud and parity, use the 'last scan' contact (%S0002) to trigger a COMREQ to restore the original port settings.