Understanding the i/o image, Understanding the i/o image -2 – Rockwell Automation 20-COMM-P Profibus Adapter User Manual

Page 52

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5-2

Using I/O Messaging

The terms input and output are defined from scanner’s point of view.
Therefore, Outputs are data that is output from the scanner and
consumed by the PROFIBUS adapter. Inputs are status data that is
produced by the adapter and consumed as input by the scanner. The I/O
image table will vary based on the following:

• Size (either 16-bit or 32-bit) of the Reference/Feedback word and

Datalink words used by the drive.

• Configuration of Parameter 11 - [DPI I/O Config] in the adapter. If

not all I/O is enabled, the image table is truncated. The image table
always uses consecutive words starting at word 0.

Figure 5.1

illustrates an example of an I/O image with 16-bit words.

Figure 5.1 Example I/O Image with All I/O Enabled

Understanding the I/O Image

Controller

Scanner

Adapter

PowerFlex Drive

PROFIBUS

DPI

Output
Image
(Write)

Input
Image
(Read)

0 Logic Status
1 Feedback
2 Datalink Out A1
3 Datalink Out A2
4 Datalink Out B1
5 Datalink Out B2
6 Datalink Out C1
7 Datalink Out C2
8 Datalink Out D1
9 Datalink Out D2

0 Logic Command

1 Reference
2 Datalink In A1
3 Datalink In A2
4 Datalink In B1
5 Datalink In B2
6 Datalink In C1
7 Datalink In C2
8 Datalink In D1
9 Datalink In D2

Logic Status
Feedback
Data Out A1
Data Out A2
Data Out B1
Data Out B2
Data Out C1
Data Out C2
Data Out D1
Data Out D2

Word and I/O

Message
Handler

Message
Handler

10 Parameter Access Word 1
11 Parameter Access Word 2
12 Parameter Access Word 3
13 Parameter Access Word 4

10 Parameter Access Word 1
11 Parameter Access Word 2
12 Parameter Access Word 3
13 Parameter Access Word 4

Logic Command

Reference
Data In A1
Data In A2
Data In B1
Data In B2
Data In C1
Data In C2
Data In D1
Data In D2

20COMM-UM006A-EN-P.book Page 2 Friday, September 28, 2001 10:43 AM

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