Siemens S5-135U/155U - Manual (Page 218)

5-78
System Manual
C79000-G8576-C199-06
The modules must be inserted at the correct slots in the central controller.
The backup battery must be fitted and in order for the CPU to start.
Step Action Result
1 Set the mode switch to STOP
2 Switch the system voltage on. The following LEDs must light
up on the CPU:
–
Red STOP LED (flashing
rapidly)
– Red BASP LED
3 Hold the MC 1) switch in the
OVERALL RESET setting
and simultaneously set the
mode switch from STOP to
RUN.
The red STOP LED is now
permanently lit.
1) MC: Momentary-contact
Step Action Result
1 Set the mode switch to STOP.
2 Hold the MC switch in the
RESET setting and
simultaneously set the mode
switch from STOP to RUN. – Red STOP LED goes off
– Green RUN LED lights up
– Red BASP LED goes off
The CPU is now in the RUN state
but still has no user program.
You can also carry out a manual restart of the CPU 922 with the mode
switch. The CPU 922 Programming Guide will indicate when a manual
restart is permissible.
Step Action Result
1 Set the mode switch from
STOP to RUN. – Red STOP LED goes off
– Green RUN LED lights up
– Red BASP LED goes off
For maintenance purposes or in the event of a fault, this startup without user
program in single-processor operation can serve to establish whether the CPU
is operating without errors.
Startup
Overall Reset
Reset
Restart
CPUs, Memory Cards, Memory Submodules, Interface Submodules