Siemens S5-135U/155U System Manual page 200

CPUs, Memory Cards, Memory Submodules, Interface Submodules
Startup
The module must be inserted at the correct slot in the central controller. The
backup battery must be fitted and in order for the CPU to start.
Overall Reset
Step
1)
Reset
Step
Restart
You can also carry out a manual restart of the CPU 928-3UA21 with the
mode switch. The CPU 928 Programming Guide will indicate when a manual
restart is permissible.
Step
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.
5-60
Action
1 Set the mode switch to STOP
2 Switch the system voltage on. The following LEDs must light
1)
3 Hold the MC switch in the
OVERALL RESET setting
and simultaneously set the
mode switch from STOP to
RUN.
MC: Momentary-contact
Action
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.
Action
1 Set the mode switch from
STOP to RUN.
Result
up on the CPU:
– Red STOP LED (flashing
rapidly)
– Red BASP LED
The red STOP LED is now
permanently lit.
Result
– 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.
Result
– Red STOP LED goes off
– Green RUN LED lights up
– Red BASP LED goes off
System Manual
C79000-G8576-C199-06