Fiber Fib


Model TC3720 
Redundant Industrial Ethernet Fiber Optic Switch

       6Tx + 2Fx Ports, 2-fiber strands


Features  Product or Application Questions (click here)

    • Ring Self-Heals within 50ms

    • Web-Based/Serial Configuration

    • IEEE 802.3, 802.3u, 802.3x Compliant

    • 6 Ethernet 10/100-Base Auto-Sensing UTP Ports

    • 2 Fiber Optic 100Base-FX Ports

    • Standard Single Mode Distance of 50km (optional 100km)

    • Multimode or Single Mode (1300/1550nm)

    • Full or Half-Duplex Operation

    • Industrial Hardened (optional)

    • Optional 2 x V.90 Modem for IP Routing

    • 12VDC, Optional 24VDC, -48VDC, 125VDC or 115/230VAC


Intended for Multidrop Self-Healing Ring topologies, the TC3720 Ethernet Fiber Optic Switch interconnects up to six 10/100M devices at each drop. The ring can consist of either multimode or single mode fibers or CAT5 UTP cables. Fault recovery time is less than 250 milliseconds.

The TC3720 offers a sophisticated Self-Healing Ring scheme. Fault conditions are detected on both Tx and Rx, upstream and downstream of each unit, and automatically re-routed to maintain Ring integrity. If both upstream and downstream fiber breaks, the Point-to-Point Protocol (PPP) can be used over the TC3720 optional internal V.90 modems to provide IP connectivity to a Server/Router through Public Switched Telephone Network.

A Web-based configuration user interface is provided to view and change network settings such as IP Address, Subnet, Gateway, Speed, Half/Full Duplex, Name, Password and other parameters. It also monitors the fiber ring status, alarm conditions, fault locations for local and remote units. The TC3720 can also be configured through a serial console (Out-of-Band).

The TC3720s store-forward switching technology eliminates the congestion problem inherent to the contention-oriented Ethernet CSMA/CD protocol. This improves predictable response times under heavy network loads.

The TC3720 offers two multimode (1300nm) or single mode (1300/1550nm) ports and six independent Ethernet 10/100-Base Auto-Sensing switched ports. There are two optional versions (Model TC3720T) for extreme temperature applications  (-20 to 70C, -40 to 80C).

Power is 12VDC, optional 24Vdc, -48Vdc, 125Vdc or 115/230VAC. Power redundancy is standard on 12Vdc. The unit is 19" rack mountable. Optical connectors can be ST, FC or SC.

TC3720 Specifications

Data Rates
10/100 Mbps (Auto-Sensing) 56K, V.90 Modem
Interface 2 Ethernet 100Base-Fx
Transmitter ELED, LASER
Receiver PIN Diode
Wavelength 1300nm Multimode
1310nm, 1550nm Single Mode
Fiber Optic Connectors ST, optional FC or SC
Loss Budget*
(1300nm, 1550nm)
Multimode (62.5/125m): 15dB
Single Mode (9/125m): 20dB
Laser Single Mode: 25dB
Ethernet Ports 6 RJ-45 Female
Interface Ethernet 10/100Base-T
Standard IEEE 802.3/3u/3x
Bit Error Rate 1 in 10^9 or better
Fault Recovery < 50 msec.
V.90 Modem (Optional)
Connector RJ11 Female
Interface V.90/V.92
Ports 2
Visual Indicators
System Status Power, Status (8
Port Status (Each Port) 10/100, Act, Link, Tx, Rx, Speed
Dry Contact Normal OPEN
Standard 12VDC @ 500mA
Optional 24VDC, -48VDC, 125VDC or 115/230VAC (with external power cube)
Operating -10 to 50C
High Temp (Optional) -20 to 70C
Hardened (Optional) -40 to 80C
Storage -40 to 90C
Humidity 95% non-condensing
Physical (Standalone/Wall Mount Unit)
Height (3.53 cm) 1.4"
Width (18.14 cm) 7.1"
Depth (16.57 cm) 6.5"
Weight (544 gm) 1.2 lbs

Typical Application (Application Questions)

The TC3720 is frequently used to interconnect Remote Terminal Units (RTUs) or Programmable Logic Controllers (PLCs) in Utility substation SCADA Networks that require multiple channels and the reliability of a Self-healing Ring Topology. It is also used for similar connectivity applications in Traffic Control, Industrial Process Control and Security System Networks.