Adapter status words – Rockwell Automation 1769-ADN Compact I/O 1769-ADN DeviceNet Adapter User Manual

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Publication 1769-UM001B-EN-P - October 2002

2-2 How Communication Takes Place and I/O Image Table Mapping

The amount of input data in the adapter’s input image for each I/O
module is based on the configuration of each I/O module done as
part of the 1769-ADN configuration. If an I/O module is configured to
have 0 words of input data, then it does not appear in the input image
of the 1769-ADN.

Adapter Status Words

The first two words (0 and 1) of the adapter input image contain the
adapter status. The adapter status consists of:

• I/O module data invalid bits - 1 status bit for each slot
• node address changed - 1 bit

...

Network READ

Network WRITE

DeviceNet Adapter

Input Image (Read Data)

Output Image (Write Data)

Read

Write

I/O Module

Slot 1

I/O Module

Slot 2

I/O Module

Slot 30

42279

Slot 30 Output Data

Slot 3 Output Data

Slot 2 Output Data

Slot 30 Input Data

Slot 3 Input Data

Slot 2 Input Data

Slot 1 Input Data

Adapter Status Words

Slot 1 Output Data

Bit:

I/O Module Data Invalid Bits

Node Address Changed Bit (NACB)

42280

lot

Word 0

Word 1

I/O Module Data Invalid Bits

Spare, not used