Ladder Logic
MVI71-DNPSNET
♦
PLC Platform
Distributed Network Protocol Interface Module
ProSoft Technology, Inc.
Page 29 of 100
September 22, 2008
3 Ladder
Logic
In This Chapter
Data .......................................................................................... 29
Ladder logic is required for application of the MVI71-DNPSNET module. Tasks
that must be handled by the ladder logic are module data transfer, special block
handling and status data receipt. Additionally, a power-up handler may be
needed to handle the initialization of the module's data and to clear any
processor fault conditions.
The sample ladder logic, on the ProSoft Solutions CD-ROM, is extensively
commented, to provide information on the purpose and function of each rung. For
most applications, the sample ladder will work without modification.
3.1 Module
Data
All data related to the MVI71-DNPSNET module is stored in a user defined data
file. It is the responsibility of the ladder logic programmer to construct all the data
files required by the program and to write the ladder logic required to interface to
these files.
3.1.1 Status
Data
When the side-connect interface is employed in the application, the status data is
automatically transferred from the module to the first file used by the interface.
The data is placed at an offset of 0 in the file and has the following format:
Word
Variable Name
Description
0
Scan Counter
Program scan counter incremented each time the program
loop is executed.
1 to 2
Product Name (ASCII)
These two words contain the product name of the module in
ASCII format.
3 to 4
Revision (ASCII)
These two words contain the product revision level of the
firmware in ASCII format.
5 to 6
Operating System
Revision (ASCII)
These two words contain the module's internal operating
system revision level in ASCII format.
7 to 8
Production Run Number
(ASCII)
These two words contain the production 'batch' number for
the particular chip in the module in ASCII format.
9
Read Block Count
Total number of blocks transferred from the module to the
processor.
10
Write Block Count
Total number of blocks transferred from the processor to the
module.
11
Parse Block Count
Total number of blocks parsed by the module that were
received from the processor.
Summary of Contents for InRax MVI71-DNPSNET
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