Position Command Value Linking (Gantry Axis) - Bosch REXROTH IndraDrive Applications Manual

DOK-INDRV*-MLD-APPLI**-AW02-EN-P
Rexroth IndraDrive Rexroth IndraMotion MLD Application Examples
7.5.4

Position Command Value Linking (Gantry Axis)

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Synchronous Multi-Axis Motion With Virtual Master Axis
Real Axis in CCD Slave Moves Synchronously to CCD Master (Gantry Group)
Example
Gantry axes are used very often to realize synchronous motion between 2 axes
by means of position command value linking.
Parameterization
CCD slave axis
In the CCD slave axis, the operation mode "drive-controlled position con‐
trol" (0x0305) has to be configured in the parameter "S‑0‑0287, Secondary
operation mode 7". As the secondary operation mode 7, because MLD-M of
the CCD master axis automatically configures the other operation modes.
As you want to move synchronously to the CCD master axis, you must set the
parameter "P‑0‑0187, Position command processing mode" to the value "0";
i.e. the position command value (S‑0‑0047) is processed within one NC cycle
(S‑0‑1001).
CCD master axis
The principle of Gantry linking is such that the value of the parameter "P‑0‑0434,
Position command value of controller" of the CCD master axis is transmitted as
the position command value (S‑0‑0047) to the CCD slave axis.
However, it is not possible to do this directly, as the transmission dead time
between CCD master axis and CCD slave axis must be compensated. It is also
necessary to compensate the processing time of the command value
(S‑0‑0047) in the CCD slave axis. The dead time compensation is realized by
means of the CCD extrapolator.
Make the following parameter setting in the CCD master axis:
CCD dead time compensation (extrapolator)
P‑0‑1616, CCD: Extrapolated cmd value
signal selection
P‑0‑0434
After the extrapolator has been parameterized, the output of the extrapolator
(corresponds to the value of the parameter "P‑0‑1618, CCD: Extrapolated com‐
mand value") must be configured as the value for the parameter "S‑0‑0047,
Position command value" in the MDT for the CCD slave (see CCD dialog).
Bosch Rexroth AG
P‑0‑1617, CCD: Number of extrapolation
steps
2
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