MVI56E-MCM ♦ ControlLogix Platform Reference
Modbus Communication Module User Manual
ProSoft Technology, Inc. Page 121 of 209
6 Reference
In This Chapter
Product Specifications ......................................................................... 121
Functional Overview ............................................................................ 124
Cable Connections .............................................................................. 144
MVI56E-MCM Database Definition ...................................................... 150
MVI56E-MCM Configuration Data ....................................................... 151
MVI56E-MCM Status Data Definition .................................................. 160
MVI56E-MCM User Defined Data Types ............................................. 161
Modbus Protocol Specification ............................................................ 168
Using the Optional Add-On Instruction ................................................ 180
Using the Sample Program - RSLogix 5000 Version 15 and earlier .... 189
6.1 Product Specifications
The MVI56E Enhanced Modbus Master/Slave Communication Modules allow
Rockwell Automation
®
ControlLogix
®
processors to easily interface with devices
using the Modbus RTU/ASCII serial communications protocol.
The MVI56E-MCM and MVI56E-MCMXT act as input/output modules on the
ControlLogix backplane, making Modbus data appear as I/O data to the
processor. Data transfer to and from the processor is asynchronous from the
communications on the Modbus network. Two independently configurable serial
ports can operate on the same or different Modbus networks. Each port can be
configured as a Modbus Master or Slave, sharing the same user-controlled,
10,000-word database.
The two modules are functionally the same. The MVI56E-MCM is designed for
standard process applications. The MVI56E-MCMXT is designed for the Logix-
XT™ control platform, allowing it to operate in extreme environments. It can
tolerate higher operating temperatures, and it also has a conformal coating to
protect it from harsh or caustic conditions.