Siemens S5-135U/155U - Manual (Page 271)

6-9
System Manual
C79000-G8576-C199-06
Action Reaction
Switch the supply voltage on. 1. The red STOP LEDs flash
rapidly on all CPUs to indicate:
Overall reset requested.
2. If the test mode is not set at the
coordinator (see Section 6.3)
and the mode switch is not at
the TEST setting:
The red BASP (output inhibit)
LED is permanently lit to
indicate: Digital outputs are
inhibited.
Symptom:
On some CPUs the STOP LED is not lit; the other CPUs are requesting
OVERALL RESET. All CPUs are emitting the BASP (output inhibit) signal.
Remedy:
Check the setting for the number of occupied CPU slots on the coordinator.
Are the CPUs inserted at suitable slots?
Executing an OVERALL RESET on all CPUs:
Ensure that the mode switch on the coordinator is set to STOP. (Precondition:
Steps 3 and 4 have been fully executed.
Action Reaction
Execute the OVERALL RESET for
each individual CPU:
Hold the MC 1) mode switch in the
OVERALL RESET setting; simulta-
neously set the mode switch from
STOP to RUN and back to STOP.
The red STOP LEDs on the CPUs at
which the OVERALL RESET was
executed, light up continuously.
Each CPU additionally emits the
output inhibit signal (BASP LED
continuously lit).
1) MC: Momentary-contact
Step 4
Possible Faults
Step 5
Multiprocessor Operation/Coordinators