Rockwell Automation 20-COMM-R Remote I/O Adapter - Manual (Page 43)

Using Discrete and Block Transfer I/O 4-7
20-COMM-R Remote I/O Adapter User Manual
Publication 20COMM-UM004D-EN-P
Block Transfer I/O Image The Block Transfer I/O image is a Block Transfer message that contains
eighteen 16-bit words. It reserves two words for the Reference/Feedback
and four words for each Datalink (in case 32-bit values are used).
Figure 4.3 Block Transfer I/O Image for 16-Bit Reference and Datalinks
Figure 4.4 Block Transfer I/O Image for 32-Bit Reference and Datalinks
LSW = Least Significant Word (bits 0…15)
MSW = Most Significant Word (bits 16…31)
Block Transfer I/O requests must be eighteen (18) words or fewer. If a
Reference or Datalink In field is not configured to be used by the adapter,
any value placed in the field will be ignored by the adapter. If a Datalink
Out field is not configured to be used by the adapter, the value of that field is
undefined. The Feedback field will always contain the Feedback from the
Word 0
1
Reference
Not Used
Feedback
0
2
3
4
5
Datalink In A1
Not Used
Datalink In A2
Not Used
Datalink Out A1
0
Datalink Out A2
0
6
7
8
9
Datalink In B1
Not Used
Datalink In B2
Not Used
Datalink Out B1
0
Datalink Out B2
0
10
11
12
13
Datalink In C1
Not Used
Datalink In C2
Not Used
Datalink Out C1
0
Datalink Out C2
0
14
15
16
17
Datalink In D1
Not Used
Datalink In D2
Not Used
Datalink Out D1
0
Datalink Out D2
0
Word 0
1
Reference (LSW)
Reference (MSW)
Feedback (LSW)
Feedback (MSW)
2
3
4
5
Datalink In A1 (LSW)
Datalink In A1 (MSW)
Datalink In A2 (LSW)
Datalink In A2 (MSW)
Datalink Out A1 (LSW)
Datalink Out A1 (MSW)
Datalink Out A2 (LSW)
Datalink Out A2 (MSW)
6
7
8
9
Datalink In B1 (LSW)
Datalink In B1 (MSW)
Datalink In B2 (LSW)
Datalink In B2 (MSW)
Datalink Out B1 (LSW)
Datalink Out B1 (MSW)
Datalink Out B2 (LSW)
Datalink Out B2 (MSW)
10
11
12
13
Datalink In C1 (LSW)
Datalink In C1 (MSW)
Datalink In C2 (LSW)
Datalink In C2 (MSW)
Datalink Out C1 (LSW)
Datalink Out C1 (MSW)
Datalink Out C2 (LSW)
Datalink Out C2 (MSW)
14
15
16
17
Datalink In D1 (LSW)
Datalink In D1 (MSW)
Datalink In D2 (LSW)
Datalink In D2 (MSW)
Datalink Out D1 (LSW)
Datalink Out D1 (MSW)
Datalink Out D2 (LSW)
Datalink Out D2 (MSW)
Block Transfer Write
Block Transfer Read
Block Transfer Write
Block Transfer Read