Allen-Bradley MicroLogix 1200 Reference Manual page 68

4-6 Programming Instructions Overview
Publication 1762-RM001C-EN-P
Indirect Addressing of Bit
0002
0003
• 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.
If a number larger than 4096 (or larger than the
NOTE
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.
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.
You must exercise extreme care when using indirect
IMPORTANT
addressing. Always be aware of the possibility of crossing
file boundaries or pointing to data that was not intended
to be used.
B3:0
[B25:0]
B3:0
10
END