Extron FOX3 SR 311 SM (part number 60-1732-22) is a lossless fiber optic scaling receiver for HDMI, USB HID, stereo audio, RS-232/IR control, and 3D sync, built to pair with an Extron FOX3 T 311 transmitter or a FOX3 Matrix fiber switcher over singlemode cable.

The SR 311's built-in scaler outputs fixed resolutions up to 4096x2160 at 60 Hz with 4:4:4 chroma sampling, or runs in bypass mode to pass the source resolution unchanged, over a single HDMI 2.0, HDCP 2.3-compliant output. Two USB type-A HID ports extend keyboard, mouse, and other HID-class peripherals back to the source, with device class filtering fixed at the factory so the port cannot be reconfigured for mass storage or other USB classes -- a security feature the SR 301's general-purpose USB 2.0 port does not have. Audio de-embeds to a digital HDMI-embedded output or a 3.5 mm analog stereo connector, with bidirectional RS-232 and IR pass-through control on the same fiber run. This lossless variant uses 1 SFP (mathematically lossless 4K/60 over one fiber), giving a maximum channel data rate of 10.0 Gbps (1 fiber). Power is internal, 100-240 VAC.

Key Capabilities

• Built-in scaler outputs fixed resolutions up to 4096x2160 at 60 Hz, or bypass mode
• 2-port USB HID hub with factory-locked device class filtering
• 20 km (12.4 miles) on singlemode fiber
• Bidirectional RS-232 and IR pass-through control
• Half-rack metal enclosure with optional rack shelf or under-desk mount

Where It Is Used

Secure workstation KVM extension in command centers and classified environments that need HDMI scaling, locked-down HID-only USB, and RS-232/IR device control over fiber specify the SR 311 alongside a matching FOX3 T 311 transmitter or FOX3 Matrix frame.

Specifications at a Glance

• Optical link: 1 SFP (mathematically lossless 4K/60 over one fiber), 1 LC connector, 20 km (12.4 miles)
• Video output: 1 HDMI, scaled or bypass, up to 4096x2160 at 60 Hz 4:4:4
• USB: 2-port USB HID hub, device class filtered
• Enclosure: 1.7" H x 8.75" W x 8.5" D (half rack wide)

Also referenced as Extron FOX3SR311SM, FOX3-SR-311-SM, part number 60173222.