Ladder logic, Module data object (bsapmoduledef), 3 ladder logic – ProSoft Technology MVI56-BSAPS User Manual
Page 37

Ladder Logic
MVI56-BSAPS ♦ ControlLogix Platform
Bristol Babcock Serial Slave Module
ProSoft Technology, Inc.
Page 37 of 83
September 22, 2008
3 Ladder
Logic
In This Chapter
Module Data Object (BSAPModuleDef) ................................................ 37
Message Data............................................................................. 40
Ladder logic is required for application of the MVI56-BSAPS 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 Object (BSAPModuleDef)
All data related to the MVI56-BSAPS 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 object has the following structure.
This object contains objects that define user data, status, and command control
data related to the module. Each of these object types is discussed in the
following topics of the document.