Ci-SF11/12/21/22 Series

RS-485 Serial Fiber Optic Repeater

1~2 RS-485 bus, according to RS-485 Protocol
2 Fiber Optic Ports, ST connector ( SC, FC Optional)
Supports Daisy-Chain and Star Fiber Optic Converter
Supports Star and dual optical Daisy-Chain topology
Supports Ring architecture for fiber redundancy,the recover cycle time<20ms
Optical fiber link failure and bus error alarm output
Support DIP Switches for setting communication rate
Input voltage: 9~36VDC, Dual redundant power input with 1500V high voltage isolation
IP40 protection, Metal case, 35mm DIN-Rail Mounting
Support -40~75°C wide operating temperature range
Overview Specifications Models Resources

Overview of RS-485 Serial Fiber Optic Repeater

Ci-SF11/12/21/22 series provides a fiber converter solution to extend RS-232 or RS-422/RS-485 transmission distance up to 2KM over multi-mode fiber or 20KM over Single mode fiber . The use of glass fiber transmission technology enables a very large transmission range and ensures optimal protection from EMC effects on the transmission path. This series adopts large-scale FPGA design and original technology, which can secures data transmission over EMI resistant fiber at speeds up to 115.2Kbps for RS-232 or up to 2Mbps for RS-485/422. 

Ci-SF11/12/21/22 series supports single and dual optical daisy network. The dual fiber inputs allow connecting multiple devices in a cascade or "daisy chain" fashion for fiber redundancy. The redundant Ring enables a very high level of transmission reliability. When fiber optic error somewhere, the system will rebuild the network link within 20ms, to guarantee the normal system communication, achieve the function of transmission self-healing protection. The system will recovery automatically after the network troubleshooting. This series products adopt Comark own R&D professional network protocol Ci-ring, no need any set, no need root knot, quickly finishing the network function of ring closing and ring opening.

Ci-SF11/12/21/22 series converter provides a fiber link monitoring function to detect the communication errors on both sides of the fiber connection. When a communication error occurs, a red LED status indicator will turn on and the alarm output will activate. 

Hardware adopts fanless, low power consumption, wide temperature and voltage design and has passed rigorous industrial standard tests, which can suit for the industrial scene environment with harsh requirements for EMC. It can be widely used in various situations like industrial control, process control and traffic control.


Specifications of RS-485 Serial Fiber Optic Repeater

Serial Port
      Interface type: standard 9 pin type D RS-485 fieldbus cable interface, conform to RS-485 protocol standard.
      Support RS-485 bus standard
      Baud Rates: 9.6Kbps, 19.2 Kbps, 45.45Kbps, 93.75Kbps, 187.5Kbps, 500Kbps
      Signal Delay (electrical interface): ≤11Bit
      Constant voltage 1000V
    Resistor: without terminal resistor, connect external when necessary

 Fiber Port

      Wave length: multi-mode 850nm/1310 nm;  single mode 1310 nm/1550nm
        Fiber type:
        multi-mode 50/125um, 62.5/125um,100/140um
      single mode 8.3/125 um, 9/125um, 10/125um
      Transmission distance: multi-mode 2km, single mode 20km
      Fiber interface type: ST/SC/FC (optional); ST (standard configuration)
        Single Fiber wavelength:
        A: Transmit wavelength is single mode 1310nm, then Receive wavelength is 1550nm
      B: Transmit wavelength is single mode 1550nm, then Receive wavelength is 1310nm
      The optical line BER: <10-9
    Signal Delay (optical interface): ≤2.3μs/node

Power Supply

DC (18~36V) dual redundant power input (can be customized with 9~18VDC)
Industrial standard voltage DC 24V, consumption is less than 1.5W
      DC 1500V voltage isolation and reverse connect protection
      5.08mm industrial terminal port
      Relay: optical fiber link failure and bus error alarm output
    Contact rating: 1 A  24V DC, Industrial Terminal port
      Dimensions (H×D×W): 136mm×104.8mm×52.8mm
      Weight: 800g
      Casing: IP40 protection, wave grain aluminum reinforce case
    Wall mounting or DIN rail mounting
      Operating Temperature:-40℃~75℃(-40℃~85℃ optional)
      Storage Temperature: -40℃~85℃
    Ambient Relative Humidity: 5%~95%(non-condensing)
    5 years
          IEC61000-4-2 (ESD): Power ±2KV Contact, ±15KV Air

        Relay ±2KV Contact, ±15KV Air; Data Cable ±15KV Air
        IEC61000-4-4 (EFT):Power ±4KV, Data Cable ±4KV
        IEC61000-4-5 (Surge):Power ±2KV CM/ ±1KV DM, Relay±2KV CM/ ±1KV DM
        IEC60068-2-27 (Shock)
        IEC60068-2-32 (Free Fall)
        IEC61000-6-2 (General Industrial Standard)

Models of RS-485 Serial Fiber Optic Repeater

Available Models


100M Fiber Port

















                 Ci-SF11/12/21/22 Series Datasheet 



                   Ci-SF11/12/21/22 Series Quick Installation Guide