ProSoft Technology MVI56E-MNETR - Manual (Page 79)

Ladder Logic MVI56E-MNETR ♦ ControlLogix Platform
User Manual Modbus TCP/IP Interface Module with Reduced Data Block
ProSoft Technology, Inc.
Page 79 of 153
August 31, 2009
3 Ladder Logic
In This Chapter
™ MNETRModuleDef ................................................................................79
™ Modbus Message Data..........................................................................84
Ladder logic is required for application of the MVI56E-MNETR 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 Import Rung with Add-On Instruction is extensively commented, to
provide information on the purpose and function of each user-defined data type
and controller tag. For most applications, the Import Rung with Add-On
Instruction will work without modification.
3.1 MNETRModuleDef
All data related to the MVI56E-MNETR 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 C
ONTROLLER T AGS E DIT T AGS
dialog box.
The following table describes the structure of the object.
Name Data Type Description
DATA MNETRDATA These objects hold data to be transferred
between the processor and the MVI56E-
MNETR module
STATUS MNETRSTATUS This object views the status of the module.
CONTROL MNETRCONTROL This object contains the data structure
required for the processor to request special
tasks from the module
UTIL MNETRUTIL This data object stores the variables required
for the data transfer between the processor
and the module.
This object contains objects that define the configuration, 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.