Siemens S5-135U/155U System Manual page 177

Status Indicators
LEDs for Fault
Indication and
Signaling
QVZ LED
System Manual
C79000-G8576-C199-06
CPUs, Memory Cards, Memory Submodules, Interface Submodules
RUN STOP Status
LED LED
on off The CPU is in the RUN state.
off on The CPU is in the STOP state. After a stop
request by switch or PG function, the STOP LED
is continuously lit because the transition to the
STOP state was requested by the user or, in
multiprocessor operation, by another CPU, and
was not caused by the CPU itself.
off off The CPU is in the INITIAL START or program
check state.
off slow The CPU is in the STOP state. The CPU has
flashing caused a transition to the STOP state (possibly
also for the other CPUs). If you set the mode
switch to STOP, the flashing LED becomes
continuously lit.
off rapid The CPU is in the STOP state. An overall reset
flashing has been requested. This request can be initiated
by the CPU itself or by operator action.
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 928B 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 928B -3UB21),
or it has been entered in DB 1 (address list) in it h b
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.
t d i DB 1 ( dd li t) i
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