Siemens SINUMERIK 840D sl Function Manual page 622

TE3: Speed/torque coupling, master-slave
16.8 Supplementary conditions
● When the coupling is switched-in (closed) via the slave axis, the master axis is braked
automatically, if the channel axis is in the same channel: ⇒ asymmetrical behavior when
activating and deactivating the coupling:
– Activate: the leading axis is automatically braked
– Deactivating: no automatic braking of the leading axis
● The setpoint position of a coupled slave axis corresponds to its actual position.
● For axes and spindles in the positioning mode, the coupling is only switched-in (closed)
and switched-out (opened) at standstill (zero speed).
● The leading-following coupling must be deactivated prior to a gear change or a star-delta
switchover.
Axial monitoring functions
● Except monitoring the speed setpoint and actual speed, axial monitoring functions like
contour and standstill in the slave axis are inactive because of the missing position
controller. The position control circuit parameters like gain factor, precontrol, balancing can
thus be set differently for master and slave axes without the monitoring functions
responding.
● In order to ensure the same braking behavior for all axes of a master-slave group, when
the coupling is active, the same alarm reaction is applied to all of the axes of the master-
slave group.
● When canceling error states, the slave axes do not reposition to the point of interruption.
Virtual axis
Master and/or slave axes must not be "virtual" axes:
MD30132 $MA_IS_VIRTUAL_AX (axis is virtual axis)
Modulo rotary axes
● For slave axes, when the coupling is closed, the actual value displayed in the service display
is not modulo 360°. Independent of the setting in machine data:
MD30310 $MA_ROT_IS_MODULO[<slave axis>]
Spindles
● If a master-slave coupling is activated with spindles, the slave spindle is operated in the
open-loop speed controlled mode. The actual value of the slave spindle is not displayed
as modulo 360° in the service display. However, in the automatic basic display the actual
value is displayed as modulo 360°.
● If the spindles are accelerated at the current limit, this may mean that no adjusting reserves
are left over in the coupled state for the torque compensatory controller to use to distribute
the torque between the master and the slave as required.
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Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Special functions