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7.4.6. Stepper motor open-loop control. Incremental encoder on load
The internal jerk units are load encoder counts / (slow loop sampling period)3. The transmission is
rotary-to-rotary. The correspondence with the load jerk in SI units is:
Load _ Jerk[SI] =
2×π
4 × No _ encoder _ lines × T 3
× Load _ Jerk[IU]
where:
No_encoder_lines – is the rotary encoder number of lines per revolution
T – is the slow loop sampling period expressed in [s]. You can read this value in the
“Advanced” dialog, which can be opened from the “Drive Setup”.
7.4.7. Stepper motor closed-loop control. Incremental encoder on motor
The internal jerk units are motor encoder counts / (slow loop sampling period)3. The
correspondence with the load jerk in SI units is:
Load _ Jerk[SI] =
2× π
4 × No _ encoder _ lines × Tr × T 3
× Motor _ Jerk[IU]
where:
No_encoder_lines – is the motor encoder number of lines per revolution
Tr – transmission ratio between the motor displacement in SI units and load displacement
in SI units
T – is the slow loop sampling period expressed in [s]. You can read this value in the
“Advanced” dialog, which can be opened from the “Drive Setup”.
7.5. Current units
The internal current units refer to the motor phase currents. The correspondence with the motor
currents in [A] is:
Current [ A ] =
2 × Ipeak
× Current [IU]
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where Ipeak – is the drive peak current expressed in [A]. You can read this value in the “Drive
Info” dialogue, which can be opened from the “Drive Setup”.
7.6. Voltage command units
The internal voltage command units refer to the voltages applied on the motor. The significance of
the voltage commands as well as the scaling factors, depend on the motor type and control
method used.
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TMC3D Technical Reference