Accessing extended i/o – Galil DMC-2X00 User Manual

Page 173

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8-Bit I/O Block

Block

Binary
Representation

Decimal Value for
Block

17-24

2

2

0

1

25-32 3

2

1

1

2

33-40 4

2

2

4

41-48 5

2

3

8

49-56 6

2

4

16

57-64 7

2

5

32

65-72 8

2

6

64

73-80 9

2

7

128

The simplest method for determining n:

Step 1. Determine which 8-bit I/O blocks to be configured as outputs.

Step 2. From the table, determine the decimal value for each I/O block to be set as an output.

Step 3. Add up all of the values determined in step 2. This is the value to be used for n.

For example, if blocks 2 and 3 are to be outputs, then n is 3 and the command, CO3, should be issued.
NOTE: This calculation is identical to the formula: n = n

2

+ 2*n

3

+ 4*n

4

+ 8*n

5

+16* n

6

+32* n

7

+64*

n

8

+128* n

9

where n

x

represents the block.

Saving the State of the Outputs in Non-Volatile Memory

The configuration of the extended I/O and the state of the outputs can be stored in the EEPROM with
the BN command. If no value has been set, the default of CO 0 is used (all blocks are inputs).

Accessing Extended I/O

When configured as an output, each I/O point may be defined with the SBn and CBn commands
(where n=1 through 8 and 17 through 80). Outputs may also be defined with the conditional
command, OBn (where n=1 through 8 and 17 through 80).

The command, OP, may also be used to set output bits, specified as blocks of data. The OP command
accepts 5 parameters. The first parameter sets the values of the main output port of the controller
(Outputs 1-8, block 0). The additional parameters set the value of the extended I/O as outlined:

OP m,a,b,c,d

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.

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

DMC-2X00

Chapter 7 Application Programming

y 163

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