Siemens S5-135U/155U User Manual

Page 191

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5-51

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

2)

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

2)

BASP: Command output inhibit

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 928B with the mode
switch. The CPU 928B Programming Guide will indicate when a manual
restart is permissible.

Step

Action

Result

3

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

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