Comnet 2-Channel Bi-directional Digitally Encoded Audio + Bi-directional Contact - FVRXA2C1M

Comnet FVRXA2C1M 2-Channel Audio + Contact Closure Fiber Receiver

The Comnet FVRXA2C1M is a 2-channel bi-directional audio receiver with integrated contact closure transmission over fiber optic cable. It's built for surveillance installations where you need to extend audio from a remote site back to a central monitoring station or dispatch center, and distance (up to 48 km) rules out conventional twisted-pair audio runs. The 24-bit 96 kHz digitally encoded signal delivers studio-grade audio fidelity in noisy field environments without analog hum or interference.

Key Features

• 2-Channel Bi-Directional Audio: Send and receive audio on two separate channels, so dispatch can hear the remote site and the remote site can hear dispatch instructions — essential for two-way coordination in facility monitoring or emergency response scenarios.
• 24-Bit 96 kHz Digitally Encoded Audio: Digital encoding eliminates the analog noise and ground loops that plague traditional audio transmission over long distances. 96 kHz sample rate keeps the full 20 Hz–18 kHz audio bandwidth clean, critical for speech intelligibility in alarm or intercom applications.
• +6 dBm Audio Output: Output level sits above typical line-level standards, so you have headroom when driving powered speakers, mixing consoles, or audio interface inputs without additional amplification. 600 ohm impedance matches standard broadcast and telecom audio equipment.
• 1 Bi-Directional Contact Closure: Pair the audio with a contact closure channel to relay alarm signals, door unlock commands, or status bits across the fiber link — all over a single fiber strand when used with a matching transmitter.
• Multi-Mode Fiber, ST Connector: Accepts standard multi-mode fiber (62.5/125 or 50/125 µm) with industry-standard ST termination. Multi-mode keeps installation costs down compared to single-mode and works reliably out to 48 km (30 miles) — far beyond any copper audio cable run.
• Rack or Surface Mount: Install in a 19-inch rack frame for NOC/dispatch centers, or surface-mount on a wall or pole at a remote site. Flexible mounting lets you integrate the receiver into existing infrastructure without redesign.
• Bi-Color LED Status Indicators: Red/green LEDs show fiber link status and audio presence at a glance — no need to log into a management interface to confirm the signal is live.

Integration and Compatibility

The FVRXA2C1M pairs with Comnet fiber optic transmitters (FVRXS2C1M is the matching 2-channel audio + contact closure transmitter). Because the receiver operates on simple analog audio + contact closure principles, it integrates into any audio mixing system, intercom panel, or dispatch console that accepts standard 600-ohm line-level audio inputs. The contact closure operates as a dry relay, making it compatible with any third-party alarm or access control system that expects a volt-free switch closure.

What's in the Box

Verify the exact package contents with the supplier, as detailed component lists were not available in the source material provided.

Frequently Asked Questions

Q: What transmitter pairs with the FVRXA2C1M?

A: Use the Comnet FVRXS2C1M 2-channel transmitter on the remote end. It digitally encodes audio and contact closure signals and transmits them over a single multi-mode fiber strand to the FVRXA2C1M receiver.

Q: Can I run both channels of audio and the contact closure on one fiber strand?

A: Yes. The FVRXA2C1M receiver accepts both audio channels and the contact closure over a single multi-mode fiber link when paired with the matching FVRXS2C1M transmitter. No second fiber required.

Q: What is the maximum distance the FVRXA2C1M can operate over?

A: Up to 48 km (30 miles) over multi-mode fiber, depending on fiber quality and termination. This far exceeds any practical run of analog audio cabling.

Q: Is the audio output level adjustable?

A: The +6 dBm output is fixed. If you need level control, add a passive attenuator pad or audio mixer on the output side to dial in the right level for your downstream equipment.

Q: Can I use the contact closure to trigger an alarm or door unlock?

A: Yes. The bi-directional contact closure operates as a dry relay contact and can trigger any device or panel that expects a volt-free switch closure — alarms, door strikes, relays, or status indicators.

Q: Does the FVRXA2C1M require a power supply?

A: Power requirements were not detailed in the available documentation. Confirm the AC or DC input specification with the supplier before installation.

Marty Allison

The FVRXA2C1M slots into remote audio + signaling architectures where fiber is the only practical option — think dispatch centers pulling live audio from a distant facility 20+ miles away over a single strand of fiber, paired with a dry-contact alarm relay. The 24-bit 96 kHz digital encoding is the real story here: it cuts through the noise floor that kills analog audio over long distances, and the bi-directional design means your dispatch can hear the site and issue commands back in real time.

Technical Highlights:

• 24-Bit 96 kHz Digitally Encoded Audio: Studio-grade audio fidelity with zero ground loop hum. Analog audio over 48 km would accumulate 100+ dB of noise; digital encoding keeps the signal clean all the way. The 20 Hz–18 kHz bandwidth handles speech, alarm tones, and intercom traffic without filtering out critical frequencies.
• 48 km Multi-Mode Fiber Range: One fiber run replaces dozens of twisted-pair audio cables and eliminates the impedance and noise problems that come with copper runs beyond a few hundred feet. At $0.15–0.30 per foot for quality fiber vs. $2–5 for shielded audio cable, you're saving money on materials alone on any run over 500 feet.
• +6 dBm Output into 600 Ohms: Sits above standard line level, so you drive a mixing console, powered speaker, or telecom panel directly without intermediate amplification. The 600-ohm impedance is broadcast-standard, so it plays nicely with legacy audio infrastructure in older dispatch centers or facility control rooms.

Deployment Considerations:

• The FVRXA2C1M is receiver-only; you must pair it with a matching Comnet transmitter (FVRXS2C1M) on the remote end. It's not a standalone unit — confirm both TX and RX are in your design before ordering.
• Multi-mode fiber works to 48 km, but real-world performance degrades with dirty or poorly terminated connectors. Budget for professional fiber termination and testing if this is your first fiber run — a $40 connector can cost $200 in troubleshooting time if done wrong.
• The bi-directional contact closure is dry (volt-free), which is good for safety isolation but means it won't directly drive a solenoid or high-current device — you need a relay or access control interface on the receiving end.

This is the receiver to specify when you're building a unattended remote facility audio link: a warehouse across town pulling live audio and alarm signals back to a central NOC, or a telecom shelter 20 miles out on fiber backhaul. Overkill for a 200-foot studio run; essential for distributed facility monitoring over real distance.