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Chapter 7 Application Programming
CDS-3310
Configuring the I/O of the CDS-3310
The 40 extended I/O points of the CDS-3310 series controller can be configured in banks of 8. The
extended I/O is denoted as banks 2-6 or bits 17-56.
The command, CO, is used to configure the extended I/O as inputs or outputs. The CO command has
one field:
CO
n
where n is a decimal value which represents a binary number. Each bit of the binary number
represents one bank of extended I/O. When set to 1, the corresponding bank is configured as an
output.
The least significant bit represents bank 2 and the most significant bit represents bank 9. The decimal
value can be calculated by the following formula. n = n
2
+ 2*n
3
+ 4*n
4
+ 8*n
5
+16* n
6
where n
x
represents the bank. If the n
x
value is a one, then the bank of 8 I/O points is to be configured as an
output. If the n
x
value is a zero, then the bank of 8 I/O points will be configured as an input. For
example, if bank 4 and 5 is to be configured as an output, CO 12 is issued.
8-Bit I/O Bank
Bank
Binary
Representation
Decimal Value for
Bank
17-24
2
2
0
1
25-32 3
2
1
2
33-40 4
2
2
4
41-48 5
2
3
8
49-56 6
2
4
16
The simplest method for determining n:
Step 1.
Determine which 8-bit I/O banks to be configured as outputs.
Step 2.
From the table, determine the decimal value for each I/O bank 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 banks 2 and 3 are to be outputs, then n is 3 and 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
where n
x
represents the
bank.
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 banks 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 56). Outputs may also be defined with the conditional
command, OBn (where n=1 through 8 and 17 through 56).
The command, OP, may also be used to set output bits, specified as banks 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, bank 0). The additional parameters set the value of the extended I/O as outlined:
OP m,a,b,c,d
Summary of Contents for CDS-3310
Page 26: ...18 i Chapter 2 Getting Started CDS 3310 THIS PAGE LEFT PLANK INTENTIONALLY...
Page 32: ...24 i Chapter 3 Connecting I O CDS 3310 THIS PAGE LEFT PLANK INTENTIONALLY...
Page 124: ...CDS 3310 Chapter 8 Hardware Software Protection i 63 THIS PAGE LEFT PLANK INTENTIONALLY...
Page 138: ...CDS 3310 Chapter 10 Theory of Operation i 77 THIS PAGE LEFT BLANK INTENTIONALLY...