Allen-Bradley PLC-2/30 - Assigning I;O Rack Numbers

Addressing
Appendix A
A7
that performs the opposite (complementary) function; an input module
complements an output module and vice-versa.
You can use an 8-point module with 16-point module in a 2-slot group;
however, it too must perform the opposite function. In this arrangement,
eight bits in the I/O image table are unused.
Assigning I/O Rack Numbers
When you select 2-slot addressing, each pair of slots (one I/O group) is
assigned to the corresponding pair of words in the input and output image
tables. You assign one I/O rack number to eight I/O groups (Figure A.5).
Figure A.5
I/O
T able and Corresponding Hardware for One Assigned Rack Number
For 2slot Addressing
Í
Í
Í
0
0
1
2
3
4
5
6
7
Word #
Output Image T able
When you select 2slot addressing
each pair of slots is assigned an
input image table word and an
output image table word.
1234567
IOIO IO IO IO IO IO IO
0
1
2
3
4
5
6
7
W
ord #
Input Image T able
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