Siemens SINUMERIK 840D sl Commissioning Manual page 803

1.2 Meaning of switch positions
Overview
The NCU has two twist buttons in the lower section of the front panel.
NCK commissioning switch
PLC mode switch
Rotary switch SVC/NCK
The switch positions have the following significance:
Switch position
PLC twist button
The switch positions have the same significance as for a SIMATIC S7-CPU:
Switch position
NCU operating system (IM7)
Commissioning Manual, 03/2013, 6FC5397-1DP40-3BA1
Operating mode of the NCK
0 Normal boot-up NCK
1 NCK boot-up with default values (= memory reset)
2 The NCK (and PLC) starts up with the data that was saved at the last
shutdown.
7 Debug mode (NCK is not started.)
8 IP address of the NCU is displayed on the seven-segment display.
All others Not relevant
Operating mode of the PLC
0 RUN
1 RUN (protected mode)
2 STOP
3 Memory reset (MRES)
All others Not relevant
System settings
1.2 Meaning of switch positions
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