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A.2 addressing modes – Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual User Manual

Page 309

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Addressing

Appendix A

AĆ2

Figure A.1

Hardware/Data Table Addressing Relationships

Concept Example

Hardware Terminology Hardware Terminology

Input (1) or Output (0)

Rack No. (1Ć7)

I/O Group No.

(0Ć7)

Terminal No.

(00Ć07, 10Ć17)

Word

Address

Bit

Address

Data Table Terminology Instruction Address

Output: 0

Rack No.: 1

Word

Address

Bit

Address

I/O Group No.: 0

Terminal No.: 12

Program Rung

|ą|

XX

(ą)

XX

XXX XXX

|ą|

11

(ą)

112 010

12

Concept

Example

The PLC-2 family processors (at the appropriate series and revision
level) can address module groups in various addressing modes. The term
“addressing mode” refers to the method of hardware addressing within
individual I/O chassis. The selected mode(s) determines the type of module
that can be used (8-point, 16-point or 32-point). The following subsections
discuss how these modes work and how you use them. (Table A.A at the
end of this appendix lists the adapters and what modes they can address.)

A.2
Addressing Modes