User Manual

CANopen Manual for TMCM-1140, TMCM-1160, and TMCM-1180 (Rev. 2.01 / 2017-JUL-26) 8
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TRINAMICS UNIQUE FEATURES – EASY TO USE WITH CANOPEN
stallGuard2™ stallGuard2 is a high-precision sensorless load measurement using the back EMF on the
coils. It can be used for stall detection as well as other uses at loads below those which
stall the motor. The stallGuard2 measurement value changes linearly over a wide range of
load, velocity, and current settings. At maximum motor load, the value goes to zero or
near to zero. This is the most energy-efficient point of operation for the motor.
Load
[Nm]
stallGuard2
Initial stallGuard2
(SG) value: 100%
Max. load
stallGuard2 (SG) value: 0
Maximum load reached.
Motor close to stall.
Motor stalls
Figure 1.1 stallGuard2 load measurement SG as a function of load
coolStep™ coolStep is a load-adaptive automatic current scaling based on the load measurement via
stallGuard2 adapting the required current to the load. Energy consumption can be reduced
by as much as 75%. coolStep allows substantial energy savings, especially for motors which
see varying loads or operate at a high duty cycle. Because a stepper motor application
needs to work with a torque reserve of 30% to 50%, even a constant-load application
allows significant energy savings because coolStep automatically enables torque reserve
when required. Reducing power consumption keeps the system cooler, increases motor
life, and allows reducing cost.
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
0 50 100 150 200 250 300 350
Efficiency
Velocity [RPM]
Efficiency with coolStep
Efficiency with 50% torque reserve
Figure 1.2 Energy efficiency example with coolStep