Galil DMC-2X00 user manual Command Summary Contour Mode, Command Description CM Abcdefgh

Command Summary - Contour Mode

COMMAND	DESCRIPTION
CM ABCDEFGH	Specifies which axes for contouring mode. Any non-contouring axes may be
	operated in other modes.
CD a,b,c,d,e,f,g,h	Specifies position increment over time interval. Range is +/-32,000. (Zero ends
	contour mode, when issued following DT0)
DT n	Specifies time interval 2n msec for position increment, where n is an integer
	between 1 and 8. Zero ends contour mode. If n does not change, it does not need
	to be specified with each CD.
WC	Waits for previous time interval to be complete before next data record is
	processed.

General Velocity Profiles

The Contour Mode is ideal for generating any arbitrary velocity profiles. The velocity profile can be specified as a mathematical function or as a collection of points.

The design includes two parts: Generating an array with data points and running the program.

Example

Generating an Array

Consider the velocity and position profiles shown in Fig. 6.7. The objective is to rotate a motor a distance of 6000 counts in 120 ms. The velocity profile is sinusoidal to reduce the jerk and the system vibration. If we describe the position displacement in terms of A counts in B milliseconds, we can describe the motion in the following manner:

ω= ΑΒ (1 − cos(2πΤ / Β))

Χ= ATB − 2Aπ sin(2πΤ / Β)

NOTE: ω is the angular velocity; A is the position; and T is the variable, time, in milliseconds. In the given example, A=6000 and B=120, the position and velocity profiles are:

A= 50T - (6000/2π) sin (2π T/120) Note that the velocity, ω, in count/ms, is

ω= 50 [1 - cos 2π T/120]

DMC-2X00 Chapter 6 Programming Motion y 57