Siemens S5-135U/155U appendix Startup

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	Action	Result

1

2

Set the mode switch to STOP

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 MC1) 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

Reset

Step

1

2

Action	Result
Set the mode switch to STOP.
Hold the MC switch in the	± Red STOP LED goes off
RESET setting and	± Green RUN LED lights up
simultaneously set the mode	± Red BASP LED goes off
switch from STOP to RUN.	The CPU is now in the RUN state
	but still has no user program.

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

1

Action

Set the mode switch from STOP to RUN.

Result

±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.

5-60	System Manual
	C79000-G8576-C199-06