CAN bus to single-mode fiber converters manual

      The CAN fiber optic converter distance and speed of optical fiber transmission aren’t related. Serial-interface fiber transmission resolves the contradiction of copper transmission’s long-distance and high-speed communications because of it’s advantages such as high reliability, security and confidentiality and so on. The use of fiber as communication transmission medium completely solves the problems such as electromagnetic interference, ground loop interference and lightning damage. It has been used more and more in industrial automation, distributed data acquisition, intelligent transportation, electricity, water, banking and many other areas and become the preferred option for communications transmission.

      FIB-CAN-S is an industrial grade CAN to fiber converter of Fourstar. It achieves CAN signal’s transparent transmission on fiber, without changing the original communication protocols and software, plug and play, and directly replace copper conductor transmission. This product is based on binary diqit transparent transmission of data, thus more suitable for the communication protocol whose physical interface is CAN.

Product characteristics and major technical indicators

● voltage: 9 ~ 40 VDC wide-voltage power supply or 5 VDC power supply optional, isolate signal interface with external power within the product through DC / DC isolation module. Power consumption: <1 W

● interface: CAN physical interface, two pairs of CANH, CANL wiring-terminal, built-in anti-lightning and anti-surge protection, repeatability

 Surge capacity: Ipp = 100A (10/700us, 4KV),standards: ITU-TK20/21, VDE 0433.

 ± 15KV ESD (electrostatic) protection

● communication rate: normal mode:0~1Mbps adaptive;enhanced mode:0~50Kbps adaptive

● the unique enhanced-drive circuit, the voltage can be doubled when outputting signals, CAN can be used for long-distance transmission of smaller communications lines

● applicable fiber: single-mode 9/125、10/125、8.3/125um

● wavelength: 1310 nm

● power of launched light: -6 dBm

● receiving sensitivity: -22 dBm

● transmission distance: 0 ~ 20km

(Maximum to 60 km or 120 km, 、 a statement is needed, with the standard FC connector)

● fiber interface: standard ST connector, SC and FC connector optional

● temperature: -40 ~ +85 ℃

● Relative Humidity: 0 to 95 percent (not condensed)

● Dimensions: 85 × 55 × 25 (L × W × H), the standard rails installation with bolts hole

● Weight: 100 g

The structure and shape of products:


The signal rank of CAN connection terminal

Terminal signal-name



CAN signal is high,the inside connect with other terminal CANH


CAN signal is low,the inside connect with other terminal CANH


CAN signal is high,the inside connect with other terminal CANH


CAN signal is low,the inside connect with other terminal CANH


CAN signal ground


Shielding ground(chassis)


Indicator light:

PWR         power            red      always shine

TXD         data sending     yellow   twinkle when sending data to fiber

RXD         data receiving   green    twinkle when receiving data from fiber

FIB          break off    red      be lighten when the fiber is broken

      There is a LED indicator FIB besides the fiber connector Rx. When the fiber is broken, the fiber is not connected or the opposite party’s fiber converters is turn off, FIB will be lit by receiving the matt signal, witch is very convenient to judge where the fault is

      Terminal resistance switch: OFF ---- no termination resistor, R ---- with 120 Ohm terminal resistance.

      Enhanced-Drive selection switch: enhancing ---when CAN sent signal, voltage is doubled; the normal --- standard CAN level when CAN sending signals

      External power: the right terminal is a two-group external power terminal, one is 9 ~ 40 VDC wide-voltage, and the other is 5 VDC fixed voltage. Any one of them is ok. You needn’t to worry about the power fluctuations. Isolating CAN signal with external power within the product through DC / DC isolation module. Thus the power supply can be taken from any power terminals of equipment or powers of different equipments, to avoid the ground loop interference caused by the 共地 of external power and CAN signal, and generate the safety of equipment.

Connection of CAN signal

      Two pairs of CANH, CANL wiring-terminal are designed for this product’s CAN port, witch can be used to eliminate the extension problems of CAN and avoid the waveform distortion caused by the signal echo on extension

The following table is the twisted pair’s cross-sectional area of the CAN’s different communication distance:

Communication distance(km)




Cross-sectional area of twisted pair (mm2)




      The settings of enhanced-drive selection switch: When the length of CAN cable is less than 5 km (two-line resistance is less than 120 Ohm), transfer the switch to "normal" position. When the length of cable is more than 5 km (two-line resistance is greater than 120 Ohm), transfer switch to "enhanced" position, at this time the relay output double-voltage signal, but will cause greater signal reflection and waveform distortion too. So thicker twisted pair is better for long-distance communications (cross-sectional area is no less than 2 mm2). Setting the switch in the "normal" working method

      When fiber converter is in the CAN bus terminal, terminal resistance switch should be transferred to R location. In other locations of the bus, the terminal resistance switch should be transferred to OFF position.

      Use fiber to link the two fiber converters. Connect Tx to the other one's Rx, Rx to the other one’s Tx.  The bend radius when laying the fiber can’t be less than the allowed one, or the core is easily broken.

      Please pay attention to maintaining the clean of fiber’s interface socket. Please

      use the configured rubber to cover it when it isn’t connected.

Typical applications map

Connect two different zones’ CAN buses by FIB-CAN fiber converters


CAN star network (fiber HUB) composed by FIB-CAN fiber converters


Fiber repeaters and fiber mode converters composed by FIB-CAN