Ladder logic, Module data, 3 ladder logic – ProSoft Technology MVI69-103M User Manual
Page 37

Ladder Logic
MVI69-103M ♦ CompactLogix or MicroLogix Platform
IEC 60870-5-103 Master Communication Module
ProSoft Technology, Inc.
Page 37 of 131
November 3, 2008
3 Ladder
Logic
In This Chapter
Data .......................................................................................... 37
Adding the Module to an Existing CompactLogix Project ...................... 45
Adding the Module to an Existing MicroLogix Project............................ 49
Ladder logic is required for application of the MVI69-103M 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
This section describes the controller tags that are defined in the example logic to
interface with the module. The user can extend these tags to meet the
specifications required for their application.
3.1.1 Module Status Data and Variables (MVI69103M_ModuleDef)
All status and variable data related to the MVI69-103M is stored in a user-defined
data type. An instance of the data type is required before the module can be
used. This is done by declaring a variable of the data type in the Controller Tags
Edit Tags dialog box. The structure of the object is displayed in the following
example:
Tag Type
Data Type
Description
DATA
MV69103M_DATA
Stores data point values
CONTROL
MVI69103M_CONTROL
Optional block handling
STATUS MVI69103M_STATUS
Stores module status
UTIL MVI69103M_UTIL
Stores convenience variables for ladder logic
usage
This object contains objects that define variables to be used with the module and
status data related to the module. Each of these object types is discussed in the
following topics of the document.