Siemens SINUMERIK 840D sl Commissioning Manual page 34

Power on and boot up
5.2 NCK and PLC general reset
Notes
Note
If a hardware RESET or POWER ON is triggered in switch position "3" on the PLC mode
selector, then the complete SRAM of the PLC is initialized and the diagnostic buffer is not
deleted. All user data must be transferred again.
If position "3" is selected for less than three seconds, no general reset is requested.
Furthermore, the STOP LED remains unlit if the sequence "2"-"3"-"2" is not completed
winthin three seconds after requesting general reset.
Note
For the first startup, module replacement, battery failure, general reset request via the PLC
and PLC upgrade, the PLC general reset is absolutely required.
Note
Since no PLC start is executed after PLC general reset, the following alarms are displayed:
• Alarm: "120201 Communication failed"
• Alarm: "380040 PROFIBUS DP: Configuring error 3, parameter"
• Alarm: "2001 PLC not booted"
These alarms have no influence on how to continue.
See also
Separate NCK and PLC general reset (Page 218)
34
Commissioning Manual, 07/2007, 6FC5397-2AP10-3BA0
IBN CNC: NCK, PLC, drive