Honeywell 2MLL-EFMT Fast Ethernet Communication Module

Product Overview

The Honeywell 2MLL-EFMT is a Fast Ethernet communication module for the MasterLogic-200 (ML200) PLC system. It enables high-speed data exchange between the ML200 controller and supervisory systems, SCADA, HMI, and peer PLCs over standard 10/100 Mbps Ethernet. Supporting TCP/IP, UDP/IP, Modbus TCP, HSP, MLDP, and EtherNet/IP, it serves as the primary communication gateway for Industry 4.0 and IIoT integration.

Key Specifications

• Product Type: Fast Ethernet Communication Module
• Series: MasterLogic-200 / ML200
• Interface: 10/100 Mbps RJ45 (auto-negotiation)
• Ethernet Standard: IEEE 802.3U (100Base-TX)
• Access Method: CSMA/CD
• Protocols Supported: TCP/IP, UDP/IP, Modbus TCP, HSP, MLDP, EtherNet/IP
• Max CIP Connections: 128 (for EtherNet/IP)
• Max Modbus TCP Connections: 16 concurrent
• Max Network Nodes: Up to 64 nodes
• IP Configuration: Static IP, DHCP, DNS, Gateway
• Software Firewall: Configurable via SoftMaster-NM
• Diagnostics: Auto scan, ping test, frame monitor, connection monitor
• LED Indicators: RUN, I/F, HS, P2P, ERR, TX, RX, 10/100 Mbps
• Dimensions (W x H x D): 22 mm x 124 mm x 126 mm
• Weight: Approx. 105 g (0.105 kg)
• Operating Temperature: 0°C to +55°C

Features & Benefits

• Multi-protocol support — native Modbus TCP, EtherNet/IP, HSP, and MLDP eliminates the need for protocol converters, reducing integration cost and complexity
• 128 CIP connections — high connection density enables simultaneous communication with multiple SCADA clients, HMIs, and peer controllers without connection pooling
• Software-configurable firewall — built-in IP filtering and access control via SoftMaster-NM protects the PLC from unauthorized network access and cyber threats
• DHCP support — dynamic IP addressing simplifies integration with existing IT infrastructure and reduces commissioning time in large plants
• Comprehensive diagnostics — auto scan, ping test, and frame monitor tools enable rapid network fault isolation without external protocol analyzers

Typical Applications

• SCADA integration for water treatment and wastewater plants
• Experion PKS/DCS integration via MLDP protocol
• Modbus TCP gateway for third-party device integration
• Peer-to-peer controller communication in distributed architectures
• IIoT data aggregation for cloud-based analytics platforms
• HMI/operator panel connectivity on packaging and assembly lines

Installation Guide

1. Install in CPU base only — the 2MLL-EFMT must be installed in the CPU main base (2MLB-MxxA); it cannot reside on expansion bases.
2. Connect Cat5e/Cat6 cable — use standard shielded twisted-pair Ethernet cable to connect the RJ45 port to your network switch or SCADA server.
3. Configure IP address — use SoftMaster-NM software to set the static IP, subnet mask, gateway, and DNS server (or enable DHCP for dynamic assignment).
4. Enable firewall rules — configure IP address filtering and port access rules to restrict unauthorized network access.
5. Select protocol — enable Modbus TCP server, HSP, or MLDP depending on your supervisory system requirements.
6. Verify communication — ping the module from your PC and confirm the I/F LED illuminates green. Test Modbus register read/write using a standard client.

FAQ

Q: What is the difference between 2MLL-EFMT and 2MLL-EFMTB?
A: The 2MLL-EFMT is the standard Fast Ethernet module. The 2MLL-EFMTB is a variant (possibly with different firmware revision or connector orientation). Both support 10/100 Mbps and identical protocols. Verify your system BOM for the exact suffix required.

Q: What is the difference between 2MLL-EFMT and 2MLL-EFMF?
A: The 2MLL-EFMT uses twisted pair (UTP/RJ45) for copper Ethernet. The 2MLL-EFMF uses fiber optic for long-distance or high-EMI Ethernet connections. Choose EFMF for >100 m runs or electrically noisy environments.

Q: Can I install this on an expansion base?
A: No. Honeywell specifies that the FEnet (Fast Ethernet) module can only reside on the CPU base. It cannot be installed on expansion bases due to backplane bandwidth allocation.

Q: What is the maximum cable distance?
A: Standard 100 meters per IEEE 802.3U 100Base-TX specification. For longer distances, use fiber optic conversion or the 2MLL-EFMF fiber Ethernet module.

Q: Does this module support OPC UA?
A: The 2MLL-EFMT supports Modbus TCP natively. For OPC UA, use an OPC server gateway (e.g., Kepware or Matrikon) that translates Modbus TCP to OPC UA.

Selection Tips

• Choose 2MLL-EFMT for standard copper Ethernet communication within 100 meters of the network switch.
• For fiber optic Ethernet (>100 m or high-EMI), select 2MLL-EFMF instead.
• Verify your SCADA protocol — if using Honeywell Experion, enable MLDP; if using third-party SCADA, enable Modbus TCP.
• Always use shielded Cat5e or Cat6 cable in industrial environments to prevent EMI-induced communication errors.
• Ensure your network switch supports 10/100 Mbps auto-negotiation; forced 1 Gbps settings will cause link failures.