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

Page 90

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Starting Your Processor

Chapter 5

5-8

Figure 5.6

Illustration of 2ĆSlot Addressing with 16ĆPoint Input and Output Modules

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11869

16Ćpoint input and output modules use

two words (one input, one output) of the

image table.

Output image table word corresponding

to the I/O group (all bits used)

Input image table word corresponding

to the I/O group (all bits used)

input

terminals

2Ćslot

I/O group

output

terminals

Because these modules use a full word in the image table, the only type of
module you can use in a 2-slot I/O group with a 16-point module is one
that performs the opposite (complementary) function; an input module
complements an output module and vice-versa.

You can use an 8-point module with a 16-point module in a 2-slot group;
however, it too must perform the opposite function. Eight bits in the I/O
image table are unused.

Important: 32-point modules will not work in 2-slot addressing mode.