Comnet SFP-3 Gigabit Ethernet Media Converter with PoE

Comnet SFP-3 Gigabit Ethernet Media Converter with PoE Support

Overview

The Comnet SFP-3, officially designated the CNGEMC4+2POE/M, is a compact surface-mount Gigabit Ethernet media converter engineered for industrial networking environments. This intelligent converter bridges copper and fiber connectivity while delivering 30W PoE+ power to edge devices, making it ideal for deployments where fiber backbone infrastructure must extend Ethernet and power to remote locations. Built for rugged industrial operation, the SFP-3 combines four Gigabit copper ports with two individually selectable SFP fiber ports in a space-efficient form factor.

Key Features

• Four 10/100/1000 BASE-T Copper Ports: Full-duplex Gigabit Ethernet connectivity on RJ45 interfaces with automatic speed negotiation.
• Two 100/1000 BASE-FX SFP Slots: Individually DIP switch selectable fiber ports supporting both 100 Mbps and Gigabit single-mode fiber, enabling flexible fiber topology configuration without hardware changes.
• 30W PoE+ Budget: Integrated power delivery across copper ports allows simultaneous powering of multiple field devices—cameras, access points, and sensors—reducing deployment infrastructure complexity.
• Intelligent Media Conversion: Automatic protocol detection and rate adaptation ensure seamless communication between copper and fiber network segments at matched speeds.
• Two Contact Closure Channels: Built-in dry contact inputs/outputs for alarm signaling and remote device triggering integration.
• Industrial-Grade Reliability: Designed for equipment-grade operation in demanding temperature and vibration environments typical of transportation, utility, and critical infrastructure networks.
• Made in USA, TAA & NDAA Compliant: Meets domestic sourcing and security compliance requirements for federal, state, and defense-adjacent deployments.
• Limited Lifetime Warranty: Manufacturer-backed coverage ensures long-term investment protection.

Technical Specifications & Performance

The SFP-3 operates at Gigabit (1000 Mbps) maximum port speed across all four copper interfaces. Fiber connectivity supports both 100 Mbps and Gigabit rates on the two SFP slots, accommodating legacy single-mode fiber installations and modern high-speed backbone links. PoE power delivery reaches 30W capacity, sufficient for powered cameras, wireless access points, and industrial sensors. The converter requires a recommended PS-A48170 power supply, with alternative PSU models PS-A48280 and PS-A48500 available for redundancy or extended power configurations.

Single-mode fiber support on both SFP ports enables long-distance, point-to-point links while maintaining Gigabit throughput. DIP switch configuration eliminates firmware updates for port mode changes, simplifying field deployment and reconfiguration. The compact surface-mount design fits standard 19-inch rack mounting and wall-mount applications without excessive footprint impact.

Integration & Compatibility

The Comnet SFP-3 integrates into multi-segment industrial networks where fiber backbone runs exist but copper Ethernet termination is required at edge nodes. Its dual-port SFP architecture allows daisy-chaining of fiber links or connection to redundant fiber rings. PoE integration eliminates separate power cables to remote copper devices, reducing installation time and point-of-failure risk. Contact closure channels enable integration with building management systems (BMS), SCADA platforms, and automated alert systems. Compatibility resources and PSU cross-reference documentation are available from Comnet to ensure proper supply selection for your deployment voltage and redundancy requirements.

Jerry Tildsen

I've specified the Comnet SFP-3 in several fiber-to-copper backbone extensions for critical infrastructure clients. This converter handles the common scenario where your core network runs single-mode fiber but you need reliable Gigabit and power delivery at remote copper endpoints. The 30W PoE budget is realistic for mid-range camera and access point deployments without exceeding thermal headroom.

Technical Highlights:

• Single-Mode Fiber Support: Both SFP ports accept single-mode transceivers, enabling long-distance runs (typically 10+ km) from your fiber backbone to edge locations without signal degradation.
• DIP Switch Port Configuration: No need to restock different firmware versions—field swap between 100 Mbps and Gigabit fiber mode by adjusting DIP switches.
• PoE Power Integration: 30W capacity means you can run a powered camera or dual access points on the copper side without additional power infrastructure at the remote site.

Deployment Considerations:

• Verify your power supply sizing matches your PoE load—the PS-A48170 is standard, but if you're running multiple high-draw devices, confirm headroom with the PSU cross-reference documentation.
• Contact closures are valuable for SCADA/BMS integration; plan your alarm signaling topology during network design phase to avoid late-stage rewiring.
• TAA and NDAA compliance makes this a safe choice for government and federally-adjacent projects where domestic sourcing is required.

For integrators deploying fiber-extend solutions into industrial or transportation networks, the SFP-3 reduces complexity by consolidating fiber-to-copper bridging and PoE delivery in one intelligent device. Its Made in USA pedigree and industrial temperature rating give confidence in long-term reliability where replacement lead times matter.