ProSoft Technology MVI94-MCM-MHI inRAX Modbus Master/Slave Communication Module

The ProSoft Technology MVI94-MCM-MHI, also cataloged as the MVI94-MCM-MHI Modbus Communication Interface Module, operates as a dedicated hardware component for serial protocol translation and data block transfers within Schneider Electric FLEX I/O backplane architectures.

Hardware Specifications

Protocol Conversion Latencies & Fieldbus Execution

The MVI94-MCM-MHI module addresses protocol conversion latencies by executing cyclic input/output data block transfers directly across the local backplane. Internal polling loops process up to 100 user-configurable command blocks, routing Modbus RTU or ASCII frame structures from field devices—such as variable frequency drives, power monitors, and flow meters—to designated host memory registers without introducing software-based handshake delays.

Deterministic timing is maintained across both serial communication ports through dedicated buffer management. Each port operates independently in RS-232, RS-422, or RS-485 modes at baud rates up to 115,200 baud, maintaining low propagation delay during bidirectional Master/Slave register updates.

Frequently Asked Questions

Q: What are the electrical constraints and backplane draw requirements for the MVI94-MCM-MHI module?

A: The module draws up to 800 mA at 5 VDC from the backplane logic bus, alongside an external power loop requirement of 340 to 170 mA across a 12 to 24 VDC operating range.

Q: How is serial line termination handled when operating RS-485 networks on Port 1 or Port 2?

A: RS-485 differential signaling requires standard external 120 ohm terminating resistors across the physical lines at both extreme physical ends of the network trunk to prevent signal reflections and line degradation at higher baud rates.

Field Installation Guidelines

1. Mount the module onto the compatible FLEX I/O terminal base unit, ensuring the locking mechanism engages firmly with the DIN-rail.
2. Verify system power is off prior to inserting or removing the communication interface card to prevent transient voltage spikes on the backplane.
3. Route RS-232/422/485 communication cables separately from high-voltage AC power lines or VFD output wiring to avoid electromagnetic interference.
4. Connect signal cable shielding to a clean single-point Earth ground (PE) at the panel entry point. Maintain shield continuity across all intermediate junction points without multipoint grounding loops.
5. Ensure operating ambient temperatures around the base unit enclosure remain within the specified range of 0 to 60 deg C with passive air convection.