ProSoft MVI56-PDPMV1 - Page 46

Start Here MVI56-PDPMV1 ♦ ControlLogix Platform
User Manual PROFIBUS DPV1 Master
Page 46 of 251 ProSoft Technology, Inc.
Scenario 3: The PROFIBUS data fits into two backplane blocks (same PROFIBUS data count
per block)
For this example, we will split the PROFIBUS data evenly within two backplane
blocks, using the following backplane configuration:
For this scenario, each backplane block reserves 50 words for PROFIBUS I/O
data. The configured PROFIBUS I/O size (100 words) will not fit into one block,
so two backplane input blocks and two backplane output blocks will be required.
Backplane Block Overview
Block
Number
Input/
Output
Total word count
in backplane
block
PROFIBUS Data
Word Count in
backplane block
Initial PROFIBUS Data
Word Offset in
backplane block
Last PROFIBUS Data
Word Offset in
backplane block
1
Input
58
50
0
49
2
Input
58
50
50
99
1
Output
55
50
0
49
2
Output
55
50
50
99
Note: This configuration would be inefficient and is therefore not recommended. The first example
(Scenario 1) is a more efficient configuration that will accomplish the same thing. This example is
here solely to illustrate how changing the I/O sizes without changing the amount of PROFIBUS
data to be transferred will affect the number of I/O data blocks the module will need to transfer.