RS-485 Bus Link Redundant Module

Provide 3 RS-485 ports
Converts non-redundant RS-485 line to two redundant lines
DIP switches for setting communication rate
Support alarm output for fieldbus ports errors
Dual redundant power input with high voltage isolation
IP40 protection rating, Metal case, 35mm DIN-Rail Mounting
Support -40~75℃ wide operating temperature range
Overview Specifications Models Resources

Overview of RS-485 Bus Link Redundant Module

This series is designed for industrial grade grade RS-485 Link Redundant Module. It realizes the mutual conversion between single bus (M port) and dual redundant bus (A, B port), either converting the single cable bus  to a redundant RS-485 bus, or the redundant RS-485 bus to a single cable bus. The data received from the M port is broadcast to the A, B port, but the A or B port data is forwarded to the M port in the first selection principle. It establish a working path at any time and monitoring the state of communication equipments in real-time. When the receiver port detects a bus fault, it will automatically switch to the redundant port. 
The field devices can be directly placed after the RS-485 master device, the single cable bus into a redundant bus. The field devices  can also be placed on the slave bus to convert the redundant bus to non-redundant cable.
The product is industrial grad designed, casing: IP40 protection, DIN rail mounting, DC (9~36V) power input, support Fieldbus ports error Relay alarm output, dual redundant power input and isolation protection. -40~75°C Operating Temperature, can meet various Industrial situation.

Specifications of RS-485 Bus Link Redundant Module

Serial Port Interface type: Type D-SUB 9 Pins
Conform to RS-485 protocol standard

Baud Rates: 9.6Kbps/19.2Kbps/45.45Kbps/93.75Kbps/187.5Kbps/500Kbps
Signal Delay (electrical interface): ≤4Bit
Isolated voltage 1KV, 4KV Anti-thunder protection
Without terminal resistor, connect external when necessary
Power Supply
      DC (9~36V) dual redundant power input
      Industrial standard voltage DC 24V, Consumption is less than 4W
      DC 1500V voltage isolation and reverse connect protection
    5.08mm pitch terminal blocks
      Relay: Fieldbus ports error Relay alarm output

    Contact rating: 1A @24V DC, Industrial Terminal port
      Dimensions (H×D×W): 136mm×104.8mm×52.8mm

      Weight: 800g

      Casing: IP40 protection, wave grain aluminum reinforce case option

      Installation: Wall mounting or DIN rail mounting


      Operating Temperature:-40℃~75℃(-40℃~85℃ optional)

      Storage Temperature: -40℃~85℃

      Ambient Relative Humidity: 5%~95%(non-condensing)


    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)
Warranty 5years

Models of RS-485 Bus Link Redundant Module

Available Models



RS-485 bus link redundancy module, 1 M port (DP3), 2 redundant bus A (DP1), B (DP2) port
DIP switch setting communication rate





  Ci-SS21 Series Datasheet 



  Ci-SS21 Series Quick Installation Guide