Rockwell Automation RECOMM-PBUS PROFIBUS Communications Module - Manual (Page 55)

Using I/O Messaging 6-3
An image that uses 32-bit words for Reference and Datalinks would
change the I/O image in figure 6.1 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 Word I/O
0 Logic
Command/Status 7 - 10 Datalink B
1 - 2 Reference/
Feedback 11 - 14 Datalink C
3 - 6 Datalink A 15 - 18 Datalink D
Figure 6.2 – Sample I/O Image with Only Logic/Reference and Datalink B Enabled
Controller Scanner Module SP600 Drive
PROFIBUS 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
Data Out D2
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
Data In D2
LSW = Least Significant Word (Bits 15 - 0)
MSW = Most Significant Word (Bits 31 - 16)