Siemens S5-135U/155U Possible Faults, Symptom, Remedy, Executing an Overall Reset on all CPUs

Multiprocessor Operation/Coordinators

Step 4

Action

Switch the supply voltage on.

Possible Faults Symptom:

Reaction

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.

	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?
Step 5	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

System Manual	6-9
C79000-G8576-C199-06