Galil DMC-3425 Example Applications, Interfacing to Grayhill or OPTO-22G4PB24, Wire Cutter

Argument	Blocks	Bits	Description
m	0	1-8	General Outputs
a	2,3	17-32	Extended I/O
b	4,5	33-48	Extended I/O
c	6,7	49-64	Extended I/O
d	8,9	65-80	Extended I/O

For example, if block 8 is configured as an output, the following command may be issued: OP 7,,,,7

This command will set bits 1,2,3 (block 0) and bits 65,66,67 (block 8) to 1. Bits 4 through 8 and bits 68 through 80 will be set to 0. All other bits are unaffected.

When accessing I/O blocks configured as inputs, use the TIn command. The argument 'n' refers to the block to be read (n=0,2,3,4,5,6,7,8 or 9). 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 80). If the following command is issued;

MG @IN[17]

the controller will return the state of the least significant bit of block 2 (assuming block 2 is configured as an input).

Interfacing to Grayhill or OPTO-22 G4PB24

The DMC-3425 2 50 Pin IDC connectors which are compatible with I/O mounting racks such as Grayhill 70GRCM32-HL and OPTO-22 G4PB24. The 50 pin ribbon cables can connect directly into the I/O mounting racks.

When using the OPTO-22 G4PB24 I/O mounting rack, the user will only have access to 48 of the 64 I/O points available on the controller. Block 5 and Block 9 must be configured as inputs and will be grounded by the I/O rack.

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 that 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.

DMC-3425 Chapter 7 Application Programming• 145