Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual User Manual

Page 92

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Starting Your Processor

Chapter 5

5-10

1ĆSlot Addressing

The processor addresses one I/O module slot as one I/O group.

Each 1-slot I/O group is represented by a word in the input image table and
a word in the output image table. You have 16 input bits and 16 output bits
available for each slot. This lets you use any mix of 8- and 16-point I/O
modules in the I/O chassis in any order. 32-point modules must be used in
complementary arrangements.

Important: For full compatibility with 1-slot addressing you must use the
series C, revision A (or later) 1770-T3 industrial terminal.

You select 1-slot addressing by setting switches 4 and 5 of the I/O chassis
backplane switch assembly:

Switch 4 to the OFF position
Switch 5 to the ON position

The physical address of each I/O group (1-slot) corresponds to an input
and an output image table word. The type of module you install (either
8-point or 16-point I/O) determines the number of bits in these words that
are used.

Figure 5.8 (on the next page) illustrates the 1-slot I/O group concept with
one 16-point I/O module. This module group uses an entire word of the
image table. You can use an 8-point I/O module with 1-slot addressing,
but the module uses only 8 bits of the I/O image table word (8 bits in the
I/O image table are unused).

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