Operand Summary - Stepper Motor Operation; Stepper Position Maintenance Mode (Spm) - Galil Motion Control DMC-1600 Series User Manual

LC
MT
RP
TD
TP

Operand Summary - Stepper Motor Operation

OPERAND
_DEx
_DPx
_ITx
_KSx
_MTx
_RPx
_TDx
_TPx

Stepper Position Maintenance Mode (SPM)

The Galil controller can be set into the Stepper Position Maintenance (SPM) mode to handle the
event of stepper motor position error. The mode looks at position feedback from the main encoder
and compares it to the commanded step pulses. The position information is used to determine if
there is any significant difference between the commanded and the actual motor positions. If such
error is detected, it is updated into a command value for operator use. In addition, the SPM mode
can be used as a method to correct for friction at the end of a microstepping move. This capability
provides closed-loop control at the application program level. SPM mode can be used with Galil
and non-Galil step drives.
SPM mode is configured, executed, and managed with seven commands. This mode also utilizes
the #POSERR automatic subroutine allowing for automatic user-defined handling of an error
event.
Internal Controller Commands (user can query):
QS
User Configurable Commands (user can query & change):
OE
YA
YB
YC
YR
YS
DMC-1600
Low Current Stepper Mode (toggles amp enable line when holding position)
Motor Type (2,-2,2.5 or -2.5 for stepper motors)
Report Commanded Position
Report number of step pulses generated by controller
Tell Position of Encoder
DESCRIPTION
Contains the value of the step count register for the 'x' axis
Contains the value of the main encoder for the 'x' axis
Contains the value of the Independent Time constant for the 'x' axis
Contains the value of the Stepper Motor Smoothing Constant for the 'x' axis
Contains the motor type value for the 'x' axis
Contains the commanded position generated by the profiler for the 'x' axis
Contains the value of the step count register for the 'x' axis
Contains the value of the main encoder for the 'x' axis
Error Magnitude (pulses)
Profiler Off-On Error
Step Drive Resolution (pulses / full motor step)
Step Motor Resolution (full motor steps / revolution)
Encoder Resolution (counts / revolution)
Error Correction (pulses)
Stepper Position Maintenance enable, status
Chapter 6 Programming Motion • 103