Siemens SINUMERIK 840D sl Function Manual page 527

Dynamic stiffness control
The Kv factor of the master axis is copied to the slave axis for an existing coupling and is thus
also active in the slave drive. This is an attempt to achieve the same control response in the
drive of the master and slave axis as far as possible. MD32640
$MA_STIFFNESS_CONTROL_ENABLE must be configured identically in all coupled axes.
Speed/torque feedforward control
The feedforward control in the slave axis does not have to be activated explicitly. The current
settings of the master axis apply. The speed feedforward value of the master axis is already
incorporated in the speed setpoint of the slave axis. For an active torque precontrol, the load-
side torque precontrol value of the master axis is also active in the slave drive.
The mechanical situation changes in coupled mode. Axial settings must be adjusted
accordingly. All coupled drives should have the same speed control dynamics.
Gantry
If one master-slave relationship is defined on each side of the gantry grouping to increase the
gain, only the leading axis or following axis may be operated as master axis.
Moving to fixed end stop
The travel to fixed stop function can be programmed only in the master axis when a coupling
is active and has a different effect on the master and slave axes.
• The programmed value is expressed as a percentage of the rated drive torque of the
master axis. The master axis detects when the fixed stop has been reached.
• The programmed value is also active on the slave axis, but refers to the drive torque of the
slave axis.
If the rated torque values of the master and slave axes are different, they can be adapted to
each other through the following slave axis machine data:
MD37014 $MA_FIXED_STOP_TORQUE_FACTOR
Specifying a factor < 1 reduces the programmed clamping torque in the slave axis.
Please note the following constraints:
• Torque distribution between the master and slave axes is not possible during clamping as
the torque compensatory controller is deactivated during clamping operations.
• Status changes to the master-slave coupling have no effect during travel to fixed stop.
Specification of a new status is only accepted when the fixed stop function has been
completed.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
TE3: Speed/torque coupling, master-slave
12.8 Constraints
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