Allen-Bradley PLC-2/30 - Instruction Address

Data Table
Chapter 3
318
If a bit is off (0), its corresponding output device is off (de-energized).
Output image table bits are controlled by user program instructions.
Instruction addresses in the input/output (I/O) image tables take the form
of Figure 3.5. These addresses have a dual role. Each 5-digit address
corresponds (1) to an input or output table word (address) and (2) to a
hardware location.
Figure 3.5 shows how the 5-digit address corresponds to an input or output
table word. The first 3 digits define the function and logical address of a
single, 16-bit input or output image table word. The remaining two digits
represent a specific bit in that I/O table word.
Figure 3.6 shows how the 5-digit address corresponds to an input or output
module terminal. Using the same 010/12 address, the first 3 digits again
define the logical function and address of a specific I/O group. The
remaining two digits represent a specific input or output terminal in that
I/O group.
NOTE: See Appendix A, Hardware Addressing, for a complete
presentation on the relationship between specified hardware terminals and
their I/O image table addresses.
3.3.2
Instruction Address
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