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Polled i/o structure, Adapter input status word – ProSoft Technology 3170-PDP User Manual

Page 20

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3170-PDP ♦ FLEX Platform

How Communication Takes Place and I/O Image Table Mapping

FLEX I/O™ PROFIBUS Adapter

Page 20 of 152

ProSoft Technology, Inc.

August 23, 2007

For example, a 16 point discrete input module will have up to 2 read words and 1
write word.

Module Image

Inputs

Input Size

Output Size

1 or 2 Words

0 or 1 Word

I/O Image

Not used

16-point Discrete Input Module

Delay

Time

Not used

Delay

Time

Refer to the I/O map for each module for the exact mapping.

3.1 Polled

I/O

Structure

The first word of output data sent by the adapter is the Adapter Status Word.
Output data is received by the adapter in the order of the installed I/O modules.
The Output data for Slot 1 is received first, followed by the Output data for Slot 2,
and so on up to slot 8. All bits in the output status word are reserved

The first word of input data sent by the adapter is the Adapter Status Word. This
is followed by the input data from each slot, in the order of the installed I/O
modules. The Input data from Slot 1 is first after the status word, followed by
Input data from Slot 2, and so on up to slot 8.

Adapter Status

Slot 1 Input Data

Slot 2 Input Data

Slot 8 Input Data

Slot 1 Output Data

Slot 2 Output Data

Slot 8 Output Data

Read Data

Write Data

Network READ

Network WRITE

PROFIBUS Adapter

Slot 1

I/O Module

Read

Write

Slot 2

I/O Module

Slot 8

I/O Module

...

...

...

...

...

Adapter Status

3.1.1 Adapter Input Status Word

The input status word consists of:
ƒ

I/O module fault bits – 1 status bit for each slot