Hello dear riends,
I have cnc milling machine with iTNC 530 controll, and I often get error "N-1 BEFARB impossible",
What is really strange, I cannot find it in any manual.
I searched the whole TNC memory and PLC program and found nothing, only logs in log file. Error numbers in plc program starts from "N4 Processor check error 3" , I cannot find N1.

To cancel the error machine control must be restarted.
Please let me know if you have some ideas.