Rockwell Automation 1769-SM1 Compact I/O to DPI/SCANport Module - Manual (Page 50)

4-2 Understanding the I/O Image
Note that the I/O words for each channel are not contiguous, with the
assumption being that the typical configuration will utilize most or all of
the channels and each channel will have a similar configuration. In these
scenarios, the required I/O space is kept to a minimum. For example, to
connect three PowerFlex 70 drives and only perform control (Logic
Command/Status and Reference/Feedback), only 12 words of I/O are
needed. Likewise, three PowerFlex drives using control and Datalink A
only require 24 words of I/O.
TIP: To minimize the amount of I/O words needed, follow these simple
rules:
1. Connect the DPI or SCANport product(s) starting with CH1,
followed by CH2, and then CH3.
2. If Datalinks are used, start with Datalink A, followed in order by B,
C, and D.
Table 4.B I/O Image Examples
Parameter 07 -
[I/O Config 1] Parameter 24 -
[I/O Config 2] Parameter 41 -
[I/O Config 3] Resulting
Number of
Input / Output
Words Used I/O Config ‘x’ Details
“00001” “00001” “00001” 12 Logic Command/Status and
Reference/Feedback only
“00011” “00011” “00011” 24 + Datalink A
“00111” “00111” “00111” 36 + Datalink B
“01111” “01111” “01111” 48 + Datalink C
“11111” “11111” “11111” 60 + Datalink D
“10001” “00001” “00001” 52 determined by CH1 Datalink D
“00001” “10001” “00001” 56 determined by CH2 Datalink D
“00001” “00001” “10001” 60 determined by CH3 Datalink D
“11111” CH2 unoccupied CH3 unoccupied 52 determined by CH1 Datalink D
CH1 unoccupied “11111” CH3 unoccupied 56 determined by CH2 Datalink D
CH1 unoccupied CH2 unoccupied “11111” 60 determined by CH3 Datalink D
TIP: To conserve I/O space in the controller, this value — rather than
the maximum size of 60 words — can be entered as the I/O size in the
RSLogix 500/5000 module configuration window.