Siemens S5-135U/155U appendix Coordinator Modes, Stop State, Event of Faults

Multiprocessor Operation/Coordinators

6.3Coordinator Modes

The Stop State	If, when the supply voltage is switched on, the coordinator mode switch is at
	STOP or another stop request is pending, the CPUs remain in the Stop state.
Startup	AUTOMATIC RESET or
	AUTOMATIC RESTART
	If, when the supply voltage is switched on, the coordinator mode switch is at
	RUN, an AUTOMATIC RESET or AUTOMATIC RESTART (depending on
	DX 0 setting) will take place as long as the mode switches of the CPUs are
	also at RUN and the PLC was previously in cyclic operation.
	MANUAL START
	When you set the coordinator mode switch from STOP to RUN, the CPUs
	will execute a start if this was already prepared at all CPUs by appropriate
	switch actuation, i.e. the CPUs are in the wait state. As required by the user,
	the type of start can be the same for all CPUs or arbitrarily different.
	After the start synchronization by the system programs, the CPUs
	simultaneously go to RUN (cyclic operation).
Normal Operation	The transition of individual CPUs is synchronized - as long as the preset
and Stop in the	ªstart synchronizationº in the relevant CPUs has not been changed by DX 0
Event of Faults	programming - i.e. only when each CPU has ended its start do all CPUs
	jointly go to cyclic program processing.
	If the coordinator mode switch is at the RUN setting and one CPU goes to
	the Stop state, all the other CPUs also go to the Stop state. The red STOP
	LED(s) on the CPU(s) causing the Stop state flash slowly; the STOP LEDs of
	the other CPUs are continuously lit.
	Apart from any indication with fault LEDs on the CPU which is the cause, all
	CPUs emit the BASP (output inhibit) signal.

System Manual	6-13
C79000-G8576-C199-06