ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 208)

Chapter 3:Unit Modes
The SimplIQ drive’s feedback can be structured in a number of different ways. These
options are called “unit modes” and are programmed by the UM parameter. The unit
mode can be switched only with the motor turned off, because the feedback structure
must be rearranged for each mode separately. The following unit modes are available:
Value Description (Related Commands)
0 Open loop voltage
1 Torque control mode
2 Speed control mode
3 Micro-stepper open loop mode
4 Dual feedback position control mode
5 Single feedback position control mode
Table 3-1: Unit Modes
3.1. Unit mode 0: Open loop voltage control
Voltage control mode
In this mode, the motor voltage is set directly by the VC software command. This mode is
useful only for very special cases, such as motors with very high resistance and very
short mechanical time constants.
Using this mode without extreme care may damage the motor.
3.2. Unit Mode 1: Torque Control
In this mode, the drive controls the motor torque only. The drive may serve as a torque
driver, controlled by an external controller.
If position sensors are connected, SimplIQ evaluates the speed for over-speed protection,
as specified by parameters LL[2] and HL[2].
The torque command may be set by a software command, an analog input or a
combination of the two, according to the following figure:
SimplIQ for Steppers Application Note Unit Modes
MAN-STECR (Ver. 1.1)
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