Eaton 9202-ETS-HN1 Modbus TCP Firewall

Eaton 9202-ETS-HN1 (Honeywell P/N 51154724-300) Industrial Modbus TCP Firewall

The Eaton MTL 9202-ETS-HN1 (Honeywell Part Number: 51154724-300, Model code: NE-FWMB01) is a ruggedized, field-proven industrial security appliance engineered to deliver deterministic Modbus TCP Deep Packet Inspection (DPI) and Layer 2/3 traffic filtering. Developed on the MTL Tofino architecture, this hardware firewall isolates safety-critical Operational Technology (OT) networks from unauthorized write commands, rogue malformed packets, and communication overloads without disrupting live plant or marine vessel automation.

Operating as a transparent network bridge (bump-in-the-wire), the 9202-ETS-HN1 requires zero network re-addressing or subnet reconfiguration. It is deployed in marine power management systems (PMS), offshore drilling instrumentation, chemical process skids, and Honeywell Experion® Process Knowledge System (PKS) loops to enforce strict read-only Modbus policies or isolate mission-critical PLCs and Remote Terminal Units (RTUs).

Model Details

• Manufacturer: Eaton
• OEM Co-Brand / Automation Partner: Honeywell Process Solutions (HPS)
• Manufacturer Part Number (MPN): 9202-ETS-HN1
• Honeywell Part Number: 51154724-300
• Hardware Model / Code: NE-FWMB01
• Predecessor Series: MTL Tofino 9211-ET-HN1
• Related Models: 51154724-400 (NE-FWMB12 / multi-protocol variant)

Technical Specifications

Features

1. Granular Modbus TCP Deep Packet Inspection: Analyzes OT traffic at the application layer, permitting specific Modbus Function Codes (e.g., Read Holding Registers FC03) while dropping prohibited write operations, illegal function requests, and broadcast storms.
2. Plug-and-Play Transparent Bridging: Functions seamlessly between controllers and SCADA/HMI without altering existing IP schemas, subnet routing, or MAC addresses.
3. Dual Redundant DC Power Inputs: Features a 9 V DC to 32 V DC operating range (SELV rated) with reverse polarity and transient overvoltage protection, preventing downtime during shipboard blackouts or supply failovers.
4. Class I, Division 2 & Zone 2 Hazardous Location Rating: Certified for deployment directly into local Zone 2 process junction boxes and offshore instrument cabinets without purging systems.
5. Integrated Hardware Fault Signaling: Onboard digital relay contact activates instantly on link loss, security policy breaches, or power rail interruption to trigger alarms in central supervisory systems.

Compatibility

• Honeywell Control Architectures: Experion PKS (C200, C300, ControlEdge PLC), Honeywell Safety Manager (FSC), TDC 3000 integration through Modbus gateways.
• Third-Party PLCs / RTUs: Schneider Electric Modicon (M340, M580, Quantum), Rockwell Automation Allen-Bradley ControlLogix via 1756-EN2T/Modbus modules, Siemens S7-1200/1500 with Open User Modbus TCP, WAGO 750 Series, and ABB AC800M.
• Marine & Off-Grid Automation: Kongsberg K-Chief, Wärtsilä Power Distribution, Rolls-Royce / Kongsberg Marine automation skids, Woodward engine governors, and Caterpillar Marine PLCs.

Applications

• Offshore & Marine Power Management Systems (PMS): Isolating critical generator protection relays and engine governors from vessel integrated automation systems (IAS).
• Honeywell Experion PKS Network Segmentation: Deploying security zones between Level 2 process control and Level 3 supervisory networks in compliance with ISA/IEC 62443.
• Oil & Gas Pipeline Skids & Tank Farm Remote Terminal Units: Securing remote unstaffed RTU Modbus communication links against packet tampering and spoofing.
• Pharmaceutical & Chemical Batch Reactors: Preventing write commands to formulation recipe setpoints while allowing continuous SCADA telemetry monitoring.
• Water & Wastewater Treatment Automation: Ring-fencing municipal pumping station PLCs operating across legacy industrial wireless and copper loops.

Frequently Asked Questions

Does installing the Eaton 9202-ETS-HN1 require reconfiguring IP addresses on our Honeywell Experion DCS?

No. The 9202-ETS-HN1 operates as a transparent Layer 2 bridging device. It does not act as a routed gateway or require IP subnetting changes. You insert it inline between the network switch and the PLC/RTU without altering current device IP addresses or network topology.

What is the primary difference between Honeywell P/N 51154724-300 and 51154724-400?

Honeywell P/N 51154724-300 (Model: NE-FWMB01) is specialized for Modbus TCP inspection (read-only and custom function code filtering). The 51154724-400 (Model: NE-FWMB12) includes expanded multi-protocol licenses and extended filtering rule capabilities for mixed industrial protocol environments.

Can this unit be mounted directly inside Class I, Division 2 hazardous area control cabinets?

Yes. The 9202-ETS-HN1 is fully certified under cULus for Class I, Division 2, Groups A, B, C, D (T4) and ATEX Zone 2 (Ex nA nC IIC T4 Gc). It does not require special nitrogen purging or explosion-proof enclosures when installed within an IP54-rated environmental cabinet.

How do you configure the firewall rules on the 9202-ETS-HN1?

Configuration is managed via the Tofino Configurator software. Encrypted profiles can be loaded over the protected network or directly transferred in the field using an authorized Tofino secure encrypted USB memory key inserted into the front USB diagnostic port.

What happens if the firewall experiences a total power outage?

The firewall defaults to a secure fail-close state to protect against undetected intrusion. Furthermore, its built-in hardware fault relay drops, immediately signaling the alarm circuit or DCS controller that safety communication has halted. Dual power feeds should always be utilized to maintain continuous plant operation.