Coordinator Modes; The Stop State; Startup; Normal Operation And Stop In The Event Of Faults - Siemens S5-155U System Manual

6.3

Coordinator Modes

The Stop state

Startup

Normal operation and Stop
in the event of faults
System Manual
C79000-B8576-C199-03
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.
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).
The transition of individual CPUs is synchronized - as long as the
preset "start synchronization" in the relevant CPUs has not been
changed by DX 0 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.

Coordinator Modes

6 - 15
6