Rockwell Automation RECOMM-IBUS Interbus Communications Module - Manual (Page 51)

Using I/O Messaging 6-3
An image that uses 32-bit words for Reference and Datalinks would
change the I/O image as follows:
Figure 6.2 illustrates an example of an I/O image that does not use
all of the I/O data. Only the Logic Command/Reference and
Datalink B are enabled. In this example, the Reference is a 32-bit
word, and Datalinks are 16-bit words.
Word I/O
0 Logic Command/Status
1 - 2 Reference/Feedback
3 - 6 Datalink A1/A2
7 - 10 Datalink B1/B2
Figure 6.2 – Sample I/O Image with Only Logic/Reference and Datalink B
Enabled
Controller Scanner Module SP600 Drive
Interbus DPI
Output
Image
(Write)
Input
Image
(Read) 0 Logic Status
1 Feedback (LSW)
2 Feedback (MSW)
3 Datalink Out B1
4 Datalink Out B2
0 Logic Command
1 Reference (LSW)
2 Reference (MSW)
3 Datalink In B1
4 Datalink In B2
Logic Status
Feedback
Data Out A1
Data Out A2
Data Out B1
Data Out B2
Data Out C1
Data Out C2
Data Out D1
Word and I/O
Logic Command
Reference
Data In A1
Data In A2
Data In B1
Data In B2
Data In C1
Data In C2
Data In D1
LSW = Least Significant Word (Bits 15 - 0)
MSW = Most Significant Word (Bits 31 - 16)