Model TC8108

8 - 128 Channel Data Fiber Optic Multiplexer



  • 8 to 64 Channels (Expandable to 128)
  • Data Rates Up to 38.4 Kbps (32 Ch.)
  • Built-In Power Redundancy
  • Optional Optical Redundancy
  • Local Dry Contact Relay Alarm
  • Built-In Test Signal Generator
  • Local & Remote Loopback Features
  • Multimode or Single Mode (850/1300/1550nm)
  • Extend telephone lines with TC1900 RS-232/Fiber Phone Extender
  • Rack Mount or Stand Alone


The TC8108 Fiber Optic Multiplexer, maximizes user flexibility by offering field interchangeable interfaces, modular expandability from 8 to 64 channels and power/optical redundancy.  It supports most popular interfaces including RS-232, RS-422, TTL, RS-485* and Dry Contact Relays.  It supports data rates up to 38.4 Kbps*.  Power redundancy is standard, optical redundancy is optional.  Both feature automatic switchover.  

Each TC8108 unit consists of an 8-channel base unit and up to seven optional 8-channel add-on PC Cards.  These PC Cards can be Stacked (in 8-Channel increments) up to 64 Channels.  A 128-Channel version is possible by using a fan-out cable to expand each RJ-11 port into two RS-232 Async channels. For units with more than 24 Ch., the TCRM191 Rackmount Card Cages are required.

Because the electrical interfaces are modular, they are interchangeable at any time--before or after installation.  A user can mix up to four different interfaces (in 2-Channel increments) on each 8-Channel card.  Each PC expansion Card is identified by a card number defined by a front panel DIP switch.

Diagnostics are extensive and include Local and Remote Loopback, 22 LEDs, and a Test Signal Generator.  LEDs include Tx, Rx, Alarm, Vcc, RxA, RxB, & PWR.  Individual Tx and Rx LEDs are provided for each channel.  The built-in test signal generator verifies both device and fiber optic link operation.  This feature benefits users by helping technicians verify that both local & remote devices and the fiber optic link are operating normally.  No other test equipment is required for link and device verification.

The TC8108 is compatible with all types and sizes of multimode (850/1300nm) or single mode (1300/1550nm) fiber optic cable.  Fiber optic connectors are ST or FC; electrical connectors are RJ-11.  Power is 12VDC or 115/230VAC with an external power cube.  An extreme temperature version (-20 to 70C), Model TC8108T, is also available.

Fiber optic connectors are ST; FC is optional. Electrical connectors are RJ11. Power is 9 to 12VDC or 115/230VAC with a power card (Model TCRMPS-01) or a power cube.  

TC8108 Specifications
Data Rates (per channel)
Async 8/16/24/32 Channels 
Async 40/48/56/64 Channels
Async 128 Channels
Sync (16 Channels with External Clock)
Sync (32-Channel Version with Ext. Clock)
Up to 38.4 Kbps
Up to 19.2 Kbps
Up to 16 Kbps
Up to 38.4 Kbps
Up to 19.2 Kbps
Channel Capacity
Async without Control 8; stackable to 64 Channels (up to 128 Channels with Fan-Out Cables)
Sync 4; stackable to 32 Channels
Transmitter LED/ELED
Receiver PIN
Wavelength 850nm/1300nm multimode
  1310nm/1550nm single mode
Fiber Optic connectors ST or FC
Loss Budget 15dB multimode 850nm/1310nm @62.5um
  15dB single mode 1310nm/1550nm @9um
Connector RJ11
Interface RS-232 (standard), RS-422, RS-485 (2 or 4 wire), Dry Contact Relay, TTL
Bit error rate 1 in l09 or better
Visual Indicators
Channel Status (each channel)

Optical Signal Status  Local Loopback,
Tx, Rx
RxA, RxB, Optic Rx, FCLK
Diagnostic Function Signal Generator
Standard 12VDC @ 600ma
Optional: 24VDC, -48VDC, or 115/230VAC with external power cube or card
Operating -100C to 500C
Hi-Temp (optional) -20 to 70C
Storage -400C to 900C
Humidity 95% non-condensing
Each PC Card Height (18.10 cm) 7.1"
  Width ((3.53 cm) 1.4"
  Depth ((24.80 cm) 9.8"
  Weight (280 gm) 8 oz.


Typical Application (Application Questions)

The TC8108 is an inexpensive, reliable and flexible method for connecting large numbers of printers, terminals and status collecting devices.  It is often used in harsh environments where EMI/RFI interference, ground loops or lightning conditions may exist. The TC8108 can also be used to extend telephone lines to remote locations with the Model TC1900 RS-232/Fiber Phone Extender.