Siemens SINAMICS S120 Function Manual page 287

A variable torque limit is effective (fixed torque limit + scaling).
0 signal from BI: p1551:
The fixed torque limit is effective.
p1552[0...n] Torque limit upper scaling without offset / M_max up offs scal
Sets the signal source for the scaling of the upper torque limit to limit the speed controller
output without considering current and power limits. A possible source is the torque preset
from the DCC diagram.
p1554[0...n] Torque limit lower scaling without offset / M_max low offsScal
Sets the signal source for the scaling of the lower torque limit to limit the speed controller
output without considering current and power limits. A possible source is the torque preset
from the DCC diagram.
Adaptation of the torque limits by means of tension controller
This method is often used in winder applications to prevent the winder from running away if
the web breaks.
For this purpose, the drive is operated with speed controller override, with the speed setpoint
being calculated as a function of diameter (see DCA block). The control signal of the tension
controller is set to the torque limits, which causes the drive to operate at the torque limit in
normal mode. In case of a web break, this prevents the tension controller from actively
building torque. The winder speed is limited by the speed setpoint.
Function diagrams (see SINAMICS S List Manual)
● 5042 Servo control, Speed controller, torque/speed pre-control with encoder
● 5060 Servo control, torque setpoint
● 5210 Servo control, speed controller without encoder
● 5610 Torque limiting/reduction/interpolator
● 5620 Motor/generator torque limit
● 6031 Vector control, pre-control balancing
● 6060 Servo control, torque setpoint
Drive Functions
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
Function modules
7.10 DCC axial winder
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