Siemens sinumerik 840D sl Function Manual page 145

The appropriate synchronized axes traverse 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 of the synchronized axes
As soon as the leading axis has approached its reference point, the synchronized axis is
automatically referenced (as for reference point approach).
References:
/FB1/ Function Manual, Basic Functions, Reference Point Approach (R1)
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. If a further synchronized axis is defined in the grouping, then this is also referenced in
the way described above.
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:
Special functions: Gantry Axes (G1)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
MD37110 $MA_GANTRY_POS_TOL_WARNING (gantry warning limit)
The gantry synchronization process is started automatically. 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 $MA_REFP_VELO_SEARCH_MARKER (creep velocity)
The position value is defined by the leading axis:
MD34100 $MA_REFP_SET_POS (reference point/destination point for distance-
coordinated system)
The absolute encoders and distanced-coded encoders of the leading axis will be set to
the current actual position of the leading axis or to the reference point by the following
machine data:
MD34330 $MA_REFP_STOP_AT_ABS_MARKER (Distancecoded linear measuring
system without destination point)
For this operation, the axes traverse at the same velocity as set for reference point
approach:
MD34070 $MA_REFP_VELO_POS (reference point positioning velocity)
As soon as all gantry axes have reached their target position (ideal position), IS "Gantry
grouping is synchronized" is set to "1" followed by re-activation of the gantry axis
coupling. The position actual value of all axes in the gantry grouping must now be
identical. The gantry synchronization process is now complete.
2.2 Referencing and synchronization of gantry axes
Detailed description
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