Technical data

STOP LED lit continuously The STOP mode was triggered by the following:
•• in the single processor mode
- the mode selector was switched from RUN to STOP
- the PLC STOP programmer function was activated
- a device fault occurred (BAU, PEU)
- an OVERALL RESET was performed
•• in the multiprocessor mode
- by switching the mode selector on the coordinator to STOP,
- by another CPU going into STOP as the result of a fault (a CPU
not causing a fault is lit continuously).
STOP LED flashes slowly
(approximately once every
two seconds)
When the STOP LED flashes slowly, this normally indicates an error.
In the multiprocessor mode, slow flashing indicates the CPU which
caused the stop mode (owing to an error).
The STOP LED flashes slowly in the following situations:
- a stop operation was programmed in the user program
- an operator error has occurred (e.g. DB 1 error, selection of an
illegal start-up type, etc.)
- programming or device errors (calling a block that is not loaded,
addressing error, timeout, operation code error etc.); the following
LEDs also light up to define the possible cause of error more
exactly:
ADF LED
QVZ LED
ZYK LED
- the END PROGRAM TEST programmer function was activated in
this CPU.
The STOP LED flashes
quickly (approximately twice
per second)
When the STOP LED flashes quickly, this is a warning that an
OVERALL RESET is being requested.
STOP Mode
CPU 928B Programming Guide
4 - 14 C79000-B8576-C898-01