PD57/60-1060 / TMCM-1060 TMCL™ Firmware Manual (V1.04 / 2011-AUG-29)
108
Copyright © 2011, TRINAMIC Motion Control GmbH & Co. KG
8.3
stallGuard2
The module is equipped with TMC262 motor driver chip. The TMC262 features load measurement that can be
used for stall detection. stallGuard2™ delivers a sensorless load measurement of the motor as well as a stall
detection signal. The measured value changes linear with the load on the motor in a wide range of load,
velocity and current settings. At maximum motor load the stallGuard™ value goes to zero. This corresponds
to a load angle of 90° between the magnetic field of the stator and magnets in the rotor. This also is the
most energy efficient point of operation for the motor.
Figure 8.1: Principle function of stallGuard2
Stall detection means that the motor will be stopped when the load gets too high. It is configured by axis
parameter #174.
Stall detection can also be used for finding the reference point.
Do not use RFS in this case.
8.4
coolStep™ related axis parameters
The figure below gives an overview of the coolStep™ related parameters. Please have in mind that the
figure shows only one example for a drive. There are parameters which concern the configuration of the
current. Other parameters are for velocity regulation and for time adjustment.
It is necessary to identify and configure the thresholds for current (I6, I7 and I183) and velocity (V182).
Furthermore the stallGuard2™ feature has to be adjusted and enabled (SG170 and SG181).
The reduction or increasing of the current in the coolStep™ area (depending on the load) has to be
configured with parameters I169 and I171.
In this chapter only basic axis parameters are mentioned which concern coolStep™ and stallGuard2™. The
complete list of axis parameters in chapter 6 contains further parameters which offer more configuration
possibilities.
motor load
(% max. torque)
stallGuard2
reading
100
200
300
400
500
600
700
800
900
1000
0
10
20
30
40
50
60
70
80
90
100
Start value depends
on motor and
operating conditions
Motor stalls above this point.
Load angle exceeds 90° and
available torque sinks.
stallGuard value reaches zero
and indicates danger of stall.
This point is set by stallGuard
threshold value SGT.
