LEDs for fault indication and
signalling
QVZ LED
on
During direct access or process image update, a
module addressed by the program no longer
acknowledges although
••
either it has acknowledged in single processor
operation upon reset of the CPU 922 in the area of
the process image (IB 0 to 127, QB 0 to 127) and
has been entered as present in the "9th track" (see
Programming Guide, CPU 922),
••
or it has been entered in DB 1 (address list) in
multiprocessor or single-processor operation and
has been recognized as present during the reset.
Possible causes
••
Module failure.
••
Module was pulled out during operation, in the
STOP state or in the Off state without a
subsequent reset.
ADF LED
on
The user program has referenced an I/O address in the
process image under which no module is inserted.
ZYK LED
on
The maximum cycle time has been exceeded.
BASP LED
on
Command output is inhibited and the digital outputs
will be directly switched to the safe state.
A detailed description of interrupt and error handling can be found in
the CPU 922 Programming Guide.
5
CPU 922
System Manual
C79000-B8576-C199-03
5 - 49
