Ać11, A.2.3 1/2ćslot addressing – Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual User Manual

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Addressing

Appendix A

AĆ11

Figure A.8

Example of 1Ćslot Addressing

Rack 1

Rack 2

I/O Group No.

I/O Group 1

Address

1 1 1

I/O Group 1

Address

121

Input
Rack

I/O Group

NOTE: When addressing a block transfer module, it must be addressed
by the lowest group number that it occupies and at slot 0. For example,
a two-slot block transfer module in rack 1, groups 2 and 3 would be
addressed (by Rack-Group-Slot) at location 120.

Also, see the appropriate block transfer module user’s manual. Block
Transfer modules must be located in the same slot pair (i.e., slots 0/1, 2/3,
4/5, etc.) or they will not work. (Some two-slot B.T. modules use the lower
slave bus on the I/O chassis backplane for intramodule communications.)

When you select 1/2-slot addressing, the processor (by way of the adapter)
addresses one-half of an I/O module slot as one I/O group. The physical
address of each I/O slot corresponds to two input and two output image
table words. the type of module you install (8, 16 or 32 I/O pts.)
determines the number of bits in these words that are used.

With 1/2-slot addressing, since 32 input bits are 32 output bits are set aside
in the processor’s image table for each slot (16 input image table bits and
16 output image table bits times 2 groups per slot = 32 of each), you may
use any mix of I/O modules (8-, 16- or 32-point) in the I/O chassis.

A.2.3
1/2ĆSlot Addressing