Siemens SINUMERIK 840D Function Manual page 774

S1: Spindles
18.3 Reference / synchronize
● Constant cutting rate (G96, G961, G97, G971)
● Spindle actual speed display
● Axis mode
● Synchronous spindle setpoint coupling
Resynchronizing the position measuring system for the spindle
In the following cases, the spindle position measurement system must be resynchronized:
● The position encoder is on the motor, a contactless proximity switch is mounted on the
spindle and the gear stage is changed. Synchronization is triggered internally once the
spindle is rotating in the new gear stage (see Synchronization procedure).
● The machine has a selector switch for a vertical and horizontal spindle. Two different
position encoders are used (one for the vertical spindle and one for the horizontal spindle),
but only one actual value input is used on the controller. When the system switches from the
vertical to the horizontal spindle, the spindle must be resynchronized.
This synchronization is initiated with the NC/PLC interface signal:
DB31, ... DBX16.4 (resynchronize spindle 1)
The spindle must be in open-loop control mode.
Restoring the position after a warm restart
For spindles with incremental position measuring systems, it is possible to buffer the actual
values after a POWER OFF and after POWER ON, to restore the position last buffered before
switching-off, in order that position-dependent functions, e.g. transformations can be restored
(see Section "Automatic restoration of the machine reference (Page 332)"). One application, for
example, is the tool retraction after a warm restart during processing with tool orientation (see
Function Manual Basic Function, Section "Tool retraction after POWER ON with orientation
transformation").
The following NC/PLC interface signals display the state of the position measuring system after
the position has been restored:
DB31, ... DBX71.4 ("Restored 1") for position measuring system 1
DB31, ... DBX71.5 ("Restored 2") for position measuring system 2
Once the tool has been retracted in JOG mode, axes whose positions have been restored are
referenced. As a consequence, signals DB31, ... DBX71.4/5 ("Restored 1/2") are deleted and
signals DB31, ... DBX60.4/5 ("Referenced/synchronized 1/2") are set.
Note
If machine data MD20700 $MC_REFP_NC_START_LOCK is set to a value of "2", then an NC
start is also possible with "restored" axis positions (in the MDI mode or when overstoring).
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or
DB31, ... DBX16.5 (resynchronize spindle 2)
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA