Siemens SINUMERIK 802D sl Function Manual page 91

Referencing process
The flowchart for referencing gantry axes using an incremental measuring system is as
follows:
Section 1:
Referencing of the leading axis
Axis-specific referencing of the gantry axes is started by the active machine function REF
when the leading axis interface signal is sent from the PLC user program:
V380x 0004.7/.6 (traversing key plus/minus)
The leading axis approaches the reference point (operational sequence as for reference
point approach).
The appropriate synchronized axis traverses in synchronism with the leading axis. Interface
signal "Referenced/synchronized" of the leading axis is output to indicate that the reference
point has been reached.
Section 2:
Referencing the synchronized axis
As soon as the leading axis has approached its reference point, the synchronized axis is
automatically referenced (as for reference point approach).
The dependency between the leading axis and synchronized axis is inverted in the control
for this phase so that the leading axis now traverses in synchronism with the synchronized
axis. IS "Referenced/synchronized" of the synchronized axis is output to indicate that the
reference point has been reached. The gantry axis dependency then reverts to its previous
status.
Section 3:
Gantry synchronization
Once all axes in the gantry grouping have been referenced, they must be synchronized with
the defined reference position. The actual position of each gantry axis is first compared to
the defined reference position of the leading axis.
The next step in the operating sequence depends on the difference calculated between the
actual values of the leading and synchronized axes:
● difference is smaller than the gantry warning limit:
Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0
Gantry synchronization is started automatically (provided that IS "Automatic
synchronization locking" has not been set). The message "Synchronization in progress
gantry grouping x" is output during this process.
All gantry axes traverse at a specific position value in the decoupled state at the velocity
set in the machine data:
MD34040 REFP_VELO_SEARCH_MARKER (shutdown speed)
6.3 Referencing and synchronizing gantry axes
Gantry axes (G1)
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