118 • Chapter 7 Application Programming DMC-1000
VEL=VE*20 Compute velocity
JG VEL Change velocity
JP #Loop Change velocity
EN End
Example Applications
Wire Cutter
An operator activates a start switch. This causes a motor to advance the wire a distance of 10". When
the motion stops, the controller generates an output signal which activates the cutter. Allowing 100 ms
for the cutting completes the cycle.
Suppose that the motor drives the wire by a roller with a 2" diameter. Also assume that the encoder
resolution is 1000 lines per revolution. Since the circumference of the roller equals 2π inches, and it
corresponds to 4000 quadrature, one inch of travel equals:
4000/2π = 637 count/inch
This implies that a distance of 10 inches equals 6370 counts, and a slew speed of 5 inches per second,
for example, equals 3185 count/sec.
The input signal may be applied to I1, for example, and the output signal is chosen as output 1. The
motor velocity profile and the related input and output signals are shown in Fig. 7.1.
The program starts at a state that we define as #A. Here the controller waits for the input pulse on I1.
As soon as the pulse is given, the controller starts the forward motion.
Upon completion of the forward move, the controller outputs a pulse for 20 ms and then waits an
additional 80 ms before returning to #A for a new cycle.
Instruction Function
#A Label
AI1 Wait for input 1
PR 6370 Distance
SP 3185 Speed
BGX Start Motion
AMX After motion is complete
SB1 Set output bit 1
WT 20 Wait 20 ms
CB1 Clear output bit 1
WT 80 Wait 80 ms
JP #A Repeat the process
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