Allen-Bradley MicroLogix 1200 Reference Manual

Publication 1762-RM001C-EN-P
4-6 Programming Instructions Overview
Indirect Addressing of Bit
•
Address: B3/[B25:0]
•
Description: In this example, the element to be used for the
indirection is B25:0. The data in B25:0 defines the bit within file B3. If
the value of location B25:0 = 1017, the XIC instruction is processed
using B3/1017.
These are only some of the examples that can be used; others include:
•
File and Element Indirection: N[N10:0]:[N25:0]
•
Input Slot Indirection: I1:[N7:0].0
Each group of instructions may or may not allow indirection. Please
review the compatibility table for each instruction to determine which
elements within an instruction support indirection.
NOTE
If a number larger than 4096 (or larger than the
number of elements in the data file) is placed in B25:0
in this example, data integrity cannot be guaranteed.
Exceeding the number of elements in the data file
would cause the file boundary to be crossed.
IMPORTANT
You must exercise extreme care when using indirect
addressing. Always be aware of the possibility of crossing
file boundaries or pointing to data that was not intended
to be used.
0002
B3:0
[B25:0]
B3:0
10
0003
END

Allen-Bradley MicroLogix 1200 Specifications

General

Series	MicroLogix 1200
Type	Programmable Logic Controller (PLC)
Mounting	DIN rail or panel mount
Programming Language	Ladder Logic
Programming Software	RSLogix 500
I/O Points	Up to 40
Communication Ports	RS-232, RS-485
Memory	6 KB user memory
Power Supply	24V DC or 120/240V AC
Expansion	Supports expansion I/O modules
Operating Temperature	0°C to 55°C (32°F to 131°F)
Dimensions	90 mm x 110 mm
Weight	0.5 kg (1.1 lbs)