Tension Torque - Siemens SINUMERIK 840D sl Function Manual

12.5

Tension torque

The tension torque is a supplementary torque which is switched to the active torque
equalization controller. This means that a mechanical tension can be established between
axes within a master-slave grouping. Establishing a tension is not only possible between the
master and a slave axis, but also between two slave axes by declaring one of the slave axes
the reference axis for the torque equalization controller.
The tension torque is entered as a percentage of the rated torque of the slave axis and is
active immediately:
MD37264 $MA_MS_TENSION_TORQUE[<slave axis>] = <tension torque>
As can be seen from the structure of the torque equalization controller (Chapter "Torque
compensatory controller [Page 512]"), the tension torque is entered via a PT1 filter. The filter
time constant is set using the following machine data:
MD37266 $MA_MS_TENSION_TORQ_FILTER_TIME[<slave axis>] = <time constant>
A value for the filter time constant greater than 0 activates the filter.
Note
Minimum tension torque
The tension torque chosen must be high enough to ensure that the resulting torque does not
drop below the minimum required tension even during acceleration.
Reducing the motor temperature rise
The tension torque can be reduced when the motor is at a standstill to reduce the motor
temperature rise.
NOTICE
If a tension torque is entered without a mechanical coupling between the master and slave
axis then this causes the axes to move.
Example 1: Static coupling and establishing a tension in pairs
A master-slave application is parameterized so that one master axis is assigned three slave
axes and a tension torque is entered for one axis pair. As a consequence, the master axis
alone does not have to establish the tension torque with respect to all of the slave axes.
Assumption regarding machine axes:
• 1. up to the 4th machine axis: AX1, AX2, AX3, AX4
Static coupling for all slave axes
• MD37262 $MA_MS_COUPLING_ALWAYS_ACTIVE[AX2] = 1
• MD37262 $MA_MS_COUPLING_ALWAYS_ACTIVE[AX3] = 1
• MD37262 $MA_MS_COUPLING_ALWAYS_ACTIVE[AX4] = 1
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
TE3: Speed/torque coupling, master-slave
12.5 Tension torque
515