Printer friendly version of this page. Find a Distributor near you.
MVI56-MBP Picture

Modbus Plus Dual Port Network Interface Module for ControlLogix


The MVI56 Modbus Plus Dual Port Network Interface Module allow Rockwell Automation ControlLogix processors to connect directly on Modbus Plus networks as a peer. The module acts as an input/output module between the Modbus Plus network and the processor. Compatible devices can be found in most industries and include devices such as drives, relays and power monitor hardware.

Features and Benefits

Compatible devices include not only Modicon PLCs (which all support the Modbus Plus protocol) but also a wide assortment of end devices licensed through the ModConnect Program. The MVI56-MBP module acts as an input/output module between the Modbus Plus network and the Rockwell Automation backplane. The data transfer from the ControlLogix processor is asynchronous from the actions on the Modbus Plus network. A 4000-word register space in the module exchanges data between the processor and the Modbus Plus network.

These modules allow Rockwell Automation platforms to connect directly on Modbus Plus networks as a peer. In addition, the modules act as slaves to processors that must read/write data from the module's memory.

Crossing all industrial boundaries, potential applications include the connection of Rockwell Automation processors to Modicon processors, and the connection of Modbus Plus speaking devices such as drives, relays, and power monitor hardware to the Rockwell Automation backplanes.


Applications using the Modbus Communication Module can be found in many industrial sectors and in the following applications:

  • Foreign device data concentrator
  • Pipelines and offshore platforms
  • Food processing
  • Mining
  • Pulp and paper


  • Single Slot - 1756 backplane compatible
  • The module is recognized as an Input/Output module and has access to processor memory for data transfer between processor and module
  • Ladder Logic is used for data transfer between module and processor. Sample ladder file included.
  • Configuration data obtained from configuration text file downloaded to module. Sample configuration file included
  • Local or remote rack
  • Communication parameters
    • Baud: 57,600 (fixed)
    • Parity: none (fixed)
    • Stop: 1 (fixed)
  •  Modbus Plus ports
    • Memory usage is user definable
    • Support for the storage and transfer of up to 4,000 registers across the backplane
    • 100 word reads and writes (max. allowed)
    • Supports all five levels of Modbus Plus routing
    • Software configurable parameters Node address: 1 to 64
    • Global out size: 0 to 32 words
    • Global in size: 0 to 32 words
    • Module data transfer: 0 to 4,000 words
    • Master command count: 0 to 100 commands
  • Function codes accepted (as a Slave): 1, 2, 3, 4, 5, 6, 15, 16
  • Function codes transmitted (as a Master): 3, 16

Global Data Specifications

The MBP module actively exchanges global in (32 words max. per node) and global out (32 words max.) data on the Modbus Plus network. Priority is given to these data types to provide a high speed mechanism for the transfer of control data.

Modbus Slave Mode Specifications

  • Supports broadcast commands from host
  • Communication error codes returned to ladder logic

Modbus Master Mode Specifications

  • Command list support of up to 100 commands
  • Conditional and continuous command list polling
  • Each command list entry is fully configurable for function register to/from addressing and word/bit count/word and byte swap
  • Event driven bit and register write commands (ladder logic controlled)
  • Supports sending of broadcast commands
  • Communication status error codes returned to ladder logic on a per command basis




Backplane Current Load

800 mA @ 5.1 VDC
3 mA @ 24 VDC

Operating Temperature

32° F to 140° F (0° C to 60° C)

Storage Temperature

--40° F to 185° F (-40° C to 85° C)


30 g Operational
50 g non-operational


5 g from 10 to 150 Hz

Relative Humidity

5% to 95% (non-condensing)

LED Indicators

Module Status

Backplane Transfer Status

Application Status

Serial Activity

Debug/Configuration port (CFG)

CFG Port (CFG)

RJ45 (DB-9M with supplied cable)

RS-232 only

Application ports (PRT1 & PRT2)

Modbus Plus Connector

Two DB9 Female Standard Modbus Plus connectors

Shipped with Unit

RJ45 to DB-9M adapter cable
6-foot RS-232 configuration cable


Ex Certificate (ATEX Directive) 79.81 kB Last Modified 11/01/2012
CB Safety 41.99 kB Last Modified 11/01/2012
Declaration of Conformity (RoHS/CE) 301.57 kB Last Modified 03/04/2018
Russian GOST-R 1.23 MB Last Modified 11/01/2012
Korean KC Registration 2.46 MB Last Modified 11/01/2012
Lloyd's Register 2.13 MB Last Modified 11/01/2012
UL/cUL; Class 1, Div 2 1.12 MB Last Modified 05/20/2014
UL/cUL; Class 1, Div 2 (Canada) 1.14 MB Last Modified 05/20/2014