Siemens S5-155U System Manual page 211

377 Memory Submodules
Inserting programmed
memory submodules
Removing memory
submodules
5 - 62
Since the contents of the inserted RAM submodule are erased with
each overall reset, proceed as follows when using programmed RAM
submodules whose contents are not to be erased:
Initial situation:
• • The CPU is in the programmable controller.
• • The power supply of the PLC is switched off.
• • The mode switch of the CPU is at STOP.
Step Action
1 Insert another, unprogrammed memory submodule in the
CPU.
2 Switch the power supply on.
3 Carry out an overall reset.
4 Switch the power supply off.
5 Remove the unprogrammed memory submodule.
6 Insert the programmed memory submodule.
7 Switch the power supply on.
8 Carry out a reset.
Before removing the RAM submodule, check whether the battery is
still in order: if the battery fault LED on the RAM submodule is lit
whilst the PLC supply voltage is switched on, the contents of the
RAM submodule will be lost when it is removed.
Initial situation:
• • The CPU is in the RUN state.
Step Action
1 Set the CPU mode switch to STOP.
2 Switch the power supply off.
3 Remove the memory submodule.
System Manual
C79000-B8576-C199-03