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.
Eden PhillipsPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
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.
