The ProSoft MVI56-MCMR, also cataloged as the MVI56-MCMR Communication Module, operates as a dedicated hardware component for serial Modbus protocol bridging within ControlLogix rack systems.

Module Configuration & Architecture

• Single-slot ControlLogix backplane compatible architecture
• Reduced data block design for remote chassis and limited bandwidth applications
• Two serial ports supporting Modbus Master and Slave configurations
• 5000-word internal data register space shared with the processor

Hardware Specifications

Protocol Conversion Latencies & Serial Bus Architecture

The module utilizes an internal 5000-word register space that decouples backplane data transfer from asynchronous Modbus network operations. Master port configurations support up to 100 user-defined commands per port with optimized polling logic for nodes experiencing communication delays. Optical isolation rated at 500 V is implemented between the serial application ports and the backplane to eliminate ground loops in heavy industrial environments. Full hardware handshaking control on PRT1 and PRT2 allows direct integration with radio telemetry, modems, and multi-drop RS-485/RS-422 topologies.

Ordering Information

• 1 x MVI56-MCMR Communication Module
• 2 x RJ45 to DB-9M serial adapter cables
• 1 x 6-foot RS-232 configuration cable
• 1 x Product documentation and resource CD

Field Installation Guidelines

• Chassis Placement: Install the module into any available slot of the ControlLogix chassis. Power must be off during insertion or removal to prevent backplane bus fault conditions.
• Wiring and Shielding: Terminate RS-485 twisted-pair cables using overall foil shields grounded at one end only to minimize electromagnetic interference from variable frequency drives.
• Configuration Port Access: Connect the CFG port via the supplied RS-232 cable to a configuration terminal running ProSoft Configuration Builder software.

Frequently Asked Questions

• Question: What is the maximum backplane current draw for the MVI56-MCMR module?

  Answer: The module draws 800 mA at 5 VDC and 3 mA at 24 VDC from the ControlLogix backplane.

• Question: Are the serial application ports optically isolated?

  Answer: Yes, ports PRT1 and PRT2 feature 500 V optical isolation from the backplane circuitry.

• Question: Does the MVI56-MCMR support pass-through messaging?

  Answer: No, pass-through functionality is not supported by the reduced data block architecture of this model.

• Question: How many Modbus commands can a master port execute?

  Answer: Each master port supports up to 100 user-configurable commands.

• Question: What baud rates are supported on the serial application ports?

  Answer: The communication parameters support baud rates from 110 to 115,200 baud depending on the active protocol.

• Question: Can the module be placed in a remote rack?

  Answer: Yes, the reduced data block format makes it specifically ideal for ControlNet or Ethernet remote rack implementations.

• Question: Which instruction is used for status and special function transfers in ladder logic?

  Answer: Unscheduled data transfers utilize the standard ControlLogix MSG instruction.

• Question: What is the storage temperature range for this hardware?

  Answer: The storage temperature limits are from -40 deg C to 85 deg C.