Delta Tau GEO BRICK LV User Manual
Geo Brick LV User Manual
Motor Setup
158
Stepper Motor Setup -- Direct Micro-Stepping
Before you start
Remember to create/edit the motor type and protection power-on PLC.
Parameters with Comments ending with -User Input require the user to enter information
pertaining to their system/hardware.
pertaining to their system/hardware.
Downloading and using the suggested M-variables is highly recommended.
The traditional direct-microstepping technique controlled with sinusoidal outputs from the Turbo PMAC
is not appropriate for motors controlled with direct-PWM outputs such as in Geo Brick LV Drives. A new
technique permits direct microstepping along with direct-PWM motor control.
is not appropriate for motors controlled with direct-PWM outputs such as in Geo Brick LV Drives. A new
technique permits direct microstepping along with direct-PWM motor control.
This technique creates a simulated position sensor and feedback loop by numerically integrating the
(velocity) command output from the servo loop. This integration requires two entries in the encoder
conversion table. The resulting simulated position value can be used for both motor phase commutation
and servo-loop feedback. Alternately, a load encoder could be used for position-loop feedback while this
simulated value is used for commutation.
Encoder Conversion Table Setup
The first entry in the encoder conversion table (ECT) for each stepper motor must read the servo-loop
output like an absolute encoder. This is done with a “parallel-read” entry of a Y/X double register (the
data is in X), unshifted and unfiltered; specifying the use of 24 bits of the 48-bit Y/X register, starting 24
bits from the low end. This is effectively like reading a 24-bit DAC register.
output like an absolute encoder. This is done with a “parallel-read” entry of a Y/X double register (the
data is in X), unshifted and unfiltered; specifying the use of 24 bits of the 48-bit Y/X register, starting 24
bits from the low end. This is effectively like reading a 24-bit DAC register.
The second entry in the ECT for each stepper motor integrates the result of the first entry.