Interaction With Other Functions - Siemens SINUMERIK 840D sl Function Manual

TE3: Speed/torque coupling, master-slave
12.8 Constraints
• If, for the master or slave axis, one of the following drive status signals is not set:
DB31, ... DBX61.7 (current controller active) == 0 OR
DB31, ... DBX61.6 (speed controller active) == 0
then, when the slave axis is at a standstill, the status signal is reset:
DB31, ... DBX96.7 (master/slave active) = 0
As soon as the master and slave axis are again in closed-loop control:
DB31, ... DBX61.7 (current controller active) == 1 AND
DB31, ... DBX61.6 (speed controller active) == 1
then for the slave axis, the status signal is again set:
DB31, ... DBX96.7 (master/slave active) = 1
• The torque equalization controller can be activated via the NC/PLC interface using:
DB31, ... DBX24.4 = 1 (torque equalization controller on)
The status of the torque equalization controller is displayed in:
DB31, ... DBX96.4 (master/slave equalization controller active)
Note
The slave axis is only closed-loop speed controlled when the coupling is closed. The NC/
PLC interface signal: DB31, ... DBX61.5 (position controller active) is no longer set.
12.8.3

Interaction with other functions

Function Generator
To calibrate the speed control circuit for a closed master-slave coupling, slave axis
MD37268 $MA_MS_TORQUE_WEIGHT_SLAVE
should be set to a smaller value. Traversing of a coupled-motion slave axis is not prevented
by the torque compensatory controller in this case.
Reference point approach
If the coupling is closed, only the master axis can be referenced. Referencing of slaves axes
is suppressed. The referencing requirement does not have to be explicitly canceled for the
slave axis in order to do this. The referencing status of coupled slave axes remains
unchanged. The slave axis position is generally not the same as the master axis position.
This difference in position is not significant. If the coupling is not closed, each axis can be
referenced separately as usual.
Compensation
Position offsets of the slave axis, such as spindle pitch errors, backlash, temperature and sag
offsets are computed but not active because there is no position controller.
Correct calculation of the backlash compensation requires that the backlash of the slave axis
is always overtraveled by the motion of the master axis in coupled mode. Disconnecting the
coupling during an axis reversal error will generate an incorrect actual value for the slave axis.
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Function Manual, 09/2011, 6FC5397-2BP40-2BA0
Special Functions