Siemens SINUMERIK 840D Function Manual page 266

G1: Gantry axes
9.3 Referencing and synchronization of gantry axes
The next step in the operating sequence depends on the difference calculated between the
actual values of the leading and synchronous axes:
● difference is smaller than the gantry warning limit:
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.
The message "Synchronization running gantry grouping x" can be suppressed with:
MD37150 $MA_GANTRY_FUNCTION_MASK Bit 2 = 1
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.
● Difference is higher than the gantry warning limit for at least one synchronous axis:
IS "Gantry synchronization read to start" is set to "1" and the message "Wait for
synchronization start of gantry grouping x" is output. The gantry synchronization process is
not started automatically in this case, but must be started explicitly by the operator or from
the PLC user program. The process is initiated by IS "Start gantry synchronization" on the
leading axis. The signal is set on the leading axis. The operational sequence is then the
same as that described above.
The following flowchart illustrates the referencing and synchronization processes.
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Axes and spindles
Function Manual, 06/2019, A5E47437747B AA