Rockwell Automation 1771ACN/B_1771ACNR/B,D17716.5.123 U.MNL CONTROLNET ADAPTER User Manual
Page 34

Addressing Modes for Your I/O
3–10
Publication 1771-6.5.123 – May 1996
NO TAG illustrates the 1/2-slot addressing concept with a 32-point
I/O module. A 32-point I/O module (with 1/2-slot I/O groups) uses
two words of the image table. When you use 8 and 16-point I/O
modules with 1/2-slot addressing, you get fewer total I/O points.
Figure 3.8
1/2-slot Addressing Concept
In p u t W o rd 0
O u tp u t W o rd 0
Im a g e T a b le
W o rd s A llo c a te d
fo r I/O G ro u p 0
In p u t W o rd 1
O u tp u t W o rd 1
Im a g e T a b le
W o rd s A llo c a te d
fo r I/O G ro u p 1
14259
#
0 0
0 2
0 4
0 6
–
1 0
1 2
1 4
1 6
–
0 0
0 2
0 4
0 6
–
1 0
1 2
1 4
1 6
–
#
0 1
0 3
0 5
0 7
–
1 1
1 3
1 5
1 7
–
0 1
0 3
0 5
0 7
–
1 1
1 3
1 5
1 7
–
U n u s e d
1 7
0
1 0
7
1 7
1 0
0
7
1 7
1 0
0
7
1 7
1 0
0
7
U n u s e d
3 2 –p o in t In p u t M o d u le
1 /2 –s lo t
I/O G ro u p
0
1 /2 –s lo t
I/O G ro u p
0
1 /2 –s lo t
I/O G ro u p
1
1 /2 –s lo t
I/O G ro u p
1
In p u t
In p u t
Table 3.C
I/O Module Combinations With 1/2-slot Addressing
I/O Chassis
Series
I/O Module Combinations Per I/O Group
Data Table Bits Used
Input Image Table Output Image Table
A, B
1 8-point input module
8
0
1 8-point output module
0
8
1 8-point input and output module
8
8
1 8-point input and 1 nondiscrete output module
16
8
1 nondiscrete input and 1 8-point output module
8
16
1 nondiscrete module
8
8
B or later only
any mix of 8, 16 and 32-point input and output modules,
nondiscrete modules, and intelligent modules
16
16