Siemens S5-135U/155U System Manual page 179

Startup
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.
Overall Reset
Step
1)
2)
Reset
Step
Restart You can also carry out a manual restart of the CPU 928B with the mode
switch. The CPU 928B -3UB21 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.
System Manual
C79000-G8576-C199-06
CPUs, Memory Cards, Memory Submodules, Interface Submodules
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
BASP: Command output inhibit
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
3 Set the mode switch from
STOP to RUN.
Result
up on the CPU:
– Red STOP LED
(flashing rapidly)
2)
– 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
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