Siemens Sinumerik 840D sl Function Manual page 108

Basics on the safety functions integrated in the system/drive
5.6 Switching the system on/off
Warning
!
System startup is a critical operating state with increased risk. In this phase,
especially when activating drives, it is not permissible that personnel are close to
the hazardous area.
Further, for vertical axes, it is very important to ensure that the drives are in a
state with the pulses cancelled.
A complete forced checking procedure is necessary after powering--up (refer to
Chapter 5.3, "Forced checking procedure").
What has to be observed when switching off?
-- When SE/SN is activated, the following applies:
The stop position is cyclically saved.
For this reason, the user should only switch--off the control when the axes/
spindles with safety functions have stopped moving.
Note
If the axis is moved with the system switched--off, then the saved stop position
no longer matches the current position. For axes with safety--related functions SE
and SN, when switching--on, a user agreement is again required after the position
has been checked.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
© Siemens AG 2015 All Rights Reserved
10/15