Galil DMC-1700 Command Summary - Jogging, Velocity, Counts/Sec, 20000, 15000, 10000, TIME ms

VELOCITY
(COUNTS/SEC)
		X axis velocity profile
20000				Y axis velocity profile
15000
10000				Z axis velocity profile
5000					TIME (ms)
0	20	40	60	80	100

Figure 6.1 - Velocity Profiles of XYZ

Notes on fig 6.1: The X and Y axis have a ‘trapezoidal’ velocity profile, while the Z axis has a ‘triangular’ velocity profile. The X and Y axes accelerate to the specified speed, move at this constant speed, and then decelerate such that the final position agrees with the command position, PR. The Z axis accelerates, but before the specified speed is achieved, must begin deceleration such that the axis will stop at the commanded position. All 3 axes have the same acceleration and deceleration rate, hence, the slope of the rising and falling edges of all 3 velocity profiles are the same.

Independent Jogging

The jog mode of motion is very flexible because speed, direction and acceleration can be changed during motion. The user specifies the jog speed (JG), acceleration (AC), and the deceleration (DC) rate for each axis. The direction of motion is specified by the sign of the JG parameters. When the begin command is given (BG), the motor accelerates up to speed and continues to jog at that speed until a new speed or stop (ST) command is issued. If the jog speed is changed during motion, the controller will make a accelerated (or decelerated) change to the new speed.

An instant change to the motor position can be made with the use of the IP command. Upon receiving this command, the controller commands the motor to a position which is equal to the specified increment plus the current position. This command is useful when trying to synchronize the position of two motors while they are moving.

Note that the controller operates as a closed-loop position controller while in the jog mode. The DMC-1700/1800 converts the velocity profile into a position trajectory and a new position target is generated every sample period. This method of control results in precise speed regulation with phase lock accuracy.

Command Summary - Jogging

COMMAND

AC x,y,z,w

BG XYZW

DC x,y,z,w

IP x,y,z,w

IT x,y,z,w

JG +/-x,y,z,w

ST XYZW

DESCRIPTION Specifies acceleration rate Begins motion Specifies deceleration rate Increments position instantly

Time constant for independent motion smoothing Specifies jog speed and direction

Stops motion

DMC-1700/1800 Chapter 6 Programming Motion • 89