Galil DMC-1700, DMC-1800 Independent Axis Positioning, Command Summary - Independent Axis

Independent Axis Positioning

In this mode, motion between the specified axes is independent, and each axis follows its own profile. The user specifies the desired absolute position (PA) or relative position (PR), slew speed (SP), acceleration ramp (AC), and deceleration ramp (DC), for each axis. On begin (BG), the DMC-1700/1800 profiler generates the corresponding trapezoidal or triangular velocity profile and position trajectory. The controller determines a new command position along the trajectory every sample period until the specified profile is complete. Motion is complete when the last position command is sent by the DMC-1700/1800 profiler. Note: The actual motor motion may not be complete when the profile has been completed, however, the next motion command may be specified.

The Begin (BG) command can be issued for all axes either simultaneously or independently. XYZ or W axis specifiers are required to select the axes for motion. When no axes are specified, this causes motion to begin on all axes.

The speed (SP) and the acceleration (AC) can be changed at any time during motion, however, the deceleration (DC) and position (PR or PA) cannot be changed until motion is complete. Remember, motion is complete when the profiler is finished, not when the actual motor is in position. The Stop command (ST) can be issued at any time to decelerate the motor to a stop before it reaches its final position.

An incremental position movement (IP) may be specified during motion as long as the additional move is in the same direction. Here, the user specifies the desired position increment, n. The new target is equal to the old target plus the increment, n. Upon receiving the IP command, a revised profile will be generated for motion towards the new end position. The IP command does not require a begin. Note: If the motor is not moving, the IP command is equivalent to the PR and BG command combination.

Command Summary - Independent Axis

COMMAND

PR X,Y,Z,W

PA x,y,z,w

SP x,y,z,w

AC x,y,z,w

DC x,y,z,w

BG XYZW

ST XYZW

IP x,y,z,w

IT x,y,z,w

AM XYZW

MC XYZW

DESCRIPTION Specifies relative distance Specifies absolute position Specifies slew speed Specifies acceleration rate Specifies deceleration rate Starts motion

Stops motion before end of move Changes position target

Time constant for independent motion smoothing Trippoint for profiler complete

Trippoint for “in position”

The lower case specifiers (x,y,z,w) represent position values for each axis.

The DMC-1700/1800 also allows use of single axis specifiers such as PRY=2000

Operand Summary - Independent Axis

OPERAND

_ACx

_DCx

_SPx

_PAx

DESCRIPTION

Return acceleration rate for the axis specified by ‘x’ Return deceleration rate for the axis specified by ‘x’ Returns the speed for the axis specified by ‘x’

Returns current destination if ‘x’ axis is moving, otherwise returns the current commanded position if in a move.

DMC-1700/1800 Chapter 6 Programming Motion • 87