Elegantly simple yet packed with an advanced feature set, the FiberPlex Technologies, FOI-7280 is a powerful problem solver when it comes to routing audio or transporting E&M signals. The unit converts line level, stereo analog audio to fiber for long or short haul transport.
In addition to the audio, a multi-format serial data connection and a bidirectional pair of contact closures are included. The combination of audio and signaling provides a seamless solution for 4-wire E&M applications.
What’s the difference between the FOI and the TD versions? Functionally, the FOI-7280 and TD-7280 are identical. The only differences are the packaging and power supply. The FOI-7280 is part of the FOI line of products designed for ruggedized military applications while the TD-7280 is housed in the commercial ‘Throw Down’ packaging.

Line Level Stereo Audio Transceiver with Serial Data and Controls (E&M)

Audio Interface:

  • Supports Balanced and Unbalanced Audio I/O
  • Supports E&M (Ear and Mouth) Types II-V
  • High Quality 24-bit audio
  • Ultra Wide 20 Hz to 45 kHz Frequency Response
  • Supports Ultrasonic Signaling Serial Interface:
  • RS-232, RS-422, RS-485 (2/4 wire)
  • Data Rates from 0 to 1 Mbps Contact Closures:
  • ‘Form C’ Contacts
  • Supports Push to Talk Advanced Routing:
  • Point to Point
  • Broadcast Mode
  • Intercom/Loop
  • Multi-channel Add/Drop Power:
  • TD includes power adapter as well as a 3-position


  • Audio Tie Lines

Various advanced routing and networking options are available via DIP switch setting. These include the following:

Point to Point Mode Basic configuration. Audio inputs one unit map directly to audio outputs on the other unit. Serial data and contact closures are a direct connection.
point to pointBroadcast Mode One unit is configured as the master, which sets the clock and sampling rate. Analog and serial inputs to the master are sent to all the slaves, which output the data on their respective ports. No communication is sent from the slaves to any other units.FOI-7280-broadcast-300x37
Intercom/Loop Mode One unit is configured as the master, which sets the clock and sampling rate. It polls the loop, with each unit in the loop adding its own input to the aggregated sample, gated by its push to talk, if enabled. When the sample returns back to the master, it then sends out that aggregated sample as the output for all units in the loop. All units forward the aggregated output around the loop until it returns to the master, which discards it. Serial data from the master is replicated on all slaves, and serial data from the slaves is aggregated to output on the master.FOI-7280-loop-300x45



Standalone Power
Requires a PSQ-4909 AC supply or PSQ-4920 DC supply
Power Supply included

Power Connection
High Reliability Lemo™ connector
Both circular DC connector and 3-postion Phoenix™ quick connect

Chassis Mounting
Uses the RMC series chassis for up to 9 units in 2U or 8 units with redundant power supply
6 units in a 1U with the optional TDR-01-AC

Mil-style sealed steel can enclosure
Durable anodized brushed aluminum


Size 2

Size 3

Size 4