Prosoft MVI56-MNETC Modbus TCP/IP Multi Client Communication Module

Product Overview

The ProSoft MVI56-MNETC is a Modbus TCP/IP Multi-Client Communication Module for the Rockwell Automation ControlLogix platform. Designed for the 1756 ControlLogix chassis, this module enables ControlLogix PACs to simultaneously operate as both Modbus TCP Client (Master) and Server (Slave), supporting up to 30 client connections and 20 server connections. With a 10/100 Mbps Ethernet port and user-definable memory mapping of up to 5000 registers, it is the ideal solution for integrating Modbus devices into ControlLogix environments.

Key Specifications

• Part Number: MVI56-MNETC
• Product Type: Modbus TCP/IP Multi-Client/Server Module
• Series: ProSoft MVI56 for ControlLogix
• Platform: Allen-Bradley ControlLogix 1756 chassis
• Ethernet Port: 1 × 10/100 Mbps RJ45 (auto-crossover)
• Modbus TCP Clients: Up to 30 simultaneous connections
• Modbus TCP Servers: Up to 20 simultaneous connections
• Memory Mapping: 5000 16-bit registers (user-definable)
• Supported Function Codes: 01, 02, 03, 04, 05, 06, 15, 16
• Backplane Current: 800 mA @ 5VDC; 3 mA @ 24VDC
• Configuration: ProSoft Configuration Builder (PCB)
• Diagnostics: LED indicators + Web server for remote monitoring
• Operating Temperature: 0°C to 60°C
• Storage Temperature: -40°C to 85°C

Features & Benefits

• Multi-Client Architecture: Connect to up to 30 Modbus TCP slave devices simultaneously from one ControlLogix rack
• Dual Role: Operates as both Client and Server, enabling peer-to-peer communication between PLCs
• Large Data Buffer: 5000-register memory map supports extensive I/O and data table transfers
• Web Server Diagnostics: Built-in HTTP server provides real-time status monitoring without additional software
• CIPconnect Support: Enables remote configuration and diagnostics via EtherNet/IP or ControlNet
• Write Protection: Hardware jumper prevents unauthorized configuration changes

Applications

• Building automation integration of HVAC controllers, VFDs, and power meters
• Water/wastewater SCADA with distributed Modbus TCP RTUs
• Solar farm inverter monitoring and control
• Oil & gas wellhead data aggregation into ControlLogix

Installation Guide

1. Power Down: Turn OFF ControlLogix rack power before installing the MVI56-MNETC
2. Slot Selection: Insert the module into any available slot on the 1756-Ax chassis
3. Ethernet Connection: Connect the RJ45 port to your plant Ethernet network using Cat 5e or better cable
4. Studio 5000 Setup: Add the module to your project using the ProSoft AOP or generic Ethernet module profile
5. PCB Configuration: Define client connections (IP addresses, function codes, register maps) and server parameters
6. Tag Mapping: Map Modbus registers to ControlLogix controller tags via the imported L5X routine
7. Network Settings: Configure IP address, subnet mask, and gateway via PCB or DHCP
8. Testing: Use ModScan or ModSim utilities to verify Modbus TCP communication before commissioning

FAQ

Q: What is the difference between MVI56-MNETC and MVI56E-MNETC?
A: The MVI56E-MNETC is the enhanced version with dual Ethernet ports, higher connection capacity, and improved diagnostics. The MVI56-MNETC provides single-port Modbus TCP connectivity.

Q: Can I use this module with CompactLogix?
A: No, the MVI56-MNETC is for ControlLogix 1756 racks only. For CompactLogix, use MVI69-MNET or MVI69-MNETC.

Q: Does it support Modbus RTU over serial?
A: The MVI56-MNETC is Ethernet-only (Modbus TCP). For serial Modbus RTU/ASCII on ControlLogix, consider MVI56-MCM or MVI56E-MCM.

Q: How do I update firmware?
A: Firmware updates are performed via the ProSoft Configuration Builder utility or through the module's web interface using a .bin file from ProSoft's website.

Selection Tips

• Calculate total client connections needed — if exceeding 30, deploy multiple MVI56-MNETC modules
• Ensure your 1756 power supply has sufficient 5V capacity (800 mA per module)
• Use managed Ethernet switches with IGMP snooping for multicast traffic optimization
• For redundant Ethernet, upgrade to MVI56E-MNETC with dual-port switch capability
• Plan IP address allocation carefully to avoid conflicts with HMI, SCADA, and other network devices