Siemens SINUMERIK 840D sl Function Manual page 91

"Axis safely referenced" state
In order to reach the axis state "axis safely referenced", the axis state "axis referenced" must
have been reached, and either
●
"User agreement (Page 92)")
or
● a saved and set user agreement and saved stop position when the system was switched
off must exist. The position associated with the saved data must match the current position
within a tolerance window. This is checked both in the drive and in the NC.
The axis state "axis safely referenced" is displayed using the SGA "axis safely referenced". A
safety-related position evaluation can only be carried out for the SE and SN functions after
this state has been reached.
Saved user agreement
The state of the user agreement function is saved in non-volatile memories. This saved user
agreement forms, together with the stop position, also saved in a non-volatile fashion, the
prerequisite for the axis state "axis safely referenced".
Saved stop position
The saved stop position data is combined with the permanently saved user agreement to form
the previous history.
The following must be noted when the stop position is saved:
The following applies when SE/SN is active:
● The stop position is cyclically saved.
● If the axis is moved with the system switched off, then the saved stop position no longer
matches the current position.
As described under "axis safely referenced" the "axis safely referenced" state can also be
achieved using a saved and set user agreement and a saved stop position. The following
conditions must be met:
● The saved user agreement must be available.
● The difference between the "reference position" (power-on position with absolute
measuring systems or reference position for incremental measuring systems) and the
saved stop position (including the traversing distance to the reference point with ERN) must
be within a tolerance window specified using the appropriate machine data.
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Basics regarding the safety functions integrated in the system/drive
the user must acknowledge the actual position using the user agreement (see Chapter
6.4 Actual value conditioning
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