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where m is the decimal representation of the bits 1-8 (values from 0 to 255) and a,b,c,d represent the
extended I/O in consecutive groups of 16 bits. (values from 0 to 65535). Arguments which are given
for I/O points which are configured as inputs will be ignored. The following table describes the
arguments used to set the state of outputs.
For example, the following command may be issued:
OP 7
This command will set bits 1,2,3 (bank 0) to 1. Bits 4 through 8 will be set to 0. All other bits are
unaffected.
When accessing I/O banks configured as inputs, use the TIn command. The argument 'n' refers to the
bank to be read (n=0,2,3,4,5,6). The value returned will be a decimal representation of the
corresponding bits.
Individual bits can be queried using the @IN[n] function (where n=1 through 8 or 17 through 56). If
the following command is issued;
the controller will return the state of the least significant bit of bank 2 (assuming bank 2 is configured
as an input).
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:
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.
CDS-3310
Argument
Banks
m
0
a
2,3
b
4,5
c
6,7
MG @IN[17]
4000/2π = 637 count/inch
Bits
Description
1-8
General Outputs
17-32
Extended I/O
33-48
Extended I/O
49-56
Extended I/O
Chapter 7 Application Programming
i
55
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