USB TO RS485 (B) User Guide


This is an industrial USB to RS485 bidirectional converter with original CH343G and SP485EEN inside. It features embedded protection circuits such as lightningproof, resettable fuse, ESD protection, and TVS diode, etc. It's pretty small in size.

The USB TO RS485 is very easy to use, allows automatic transceiving. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for industrial control equipments and/or applications with high communication requirement.


  • USB to RS485 communication

  • Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic

  • Onboard self-recovery fuse and protection diodes, ensures the current/voltage stable outputs, provides over-current/over-voltage proof, improves shock resistance

  • 3 LEDs for indicating the power and transceiver status


  • Product type: industrial converter

  • Baudrate: 300-921600bps

  • Host port: USB

  • Device port:  RS485

  • USB:
    • Operating voltage: 5V

    • Connector: USB-A

    • Protection: 200mA self-recovery fuse, ESD protection

    • Transmission distance: about 5m

  • RS485:
    • Connector: screw terminal

    • Pins: A+, B-, GND

    • Direction control: hardware automatic control

    • Protection: 600W lightningproof and surge-suppress, 15KV ESD protection (onboard 120R balancing resistor)

    • Transmission distance: about 1200m (low rate)

    • Transmission mode: point-to-multipoints (up to 32 nodes, it is recommended to use repeaters for 16 nodes or more)

  • LED indicators:
    • PWR: red power indicator, light up when there is USB connection and voltage is detected

    • TXD: red TX indicator, light up when the USB port sends data

    • RXD: red RX indicator, light up when the device ports send data back

  • Operating environment:
    • Temperature: -15℃ ~ 70℃

    • Humidity: 5%RH ~ 95%RH

  • Operating system: Mac, Linux, Android, WinCE, Windows 11 / 10 / 8.1 / 8 / 7 / XP

Price: $9.89
Part Number: USB TO RS485 (B)
Brand: Spotpear
SKU: 0203044