Galil DMC-2X00 - Manual (Page 112)

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 2 n 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:
( )
) / 2 cos( 1 Β Τ −
Β
Α
= π ω
) / 2 sin(
2
Β Τ − = Χ π
π
A
B
AT
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 - (6000/2
π
) sin (2
π
T/120)
Note that the velocity,
ω
, in count/ms, is
ω
= 50 [1 - cos 2
π
T/120]
102
• Chapter 6 Programming Motion
DMC-2X00