PRODUCTS > USB to RS-422/485 > Compact > USB-COMi+2


Products Manual
  • USB-COMi+
  • USB-COMi+2
USB-COMi+2 - 1-Port RS-422/485 USB-to-Serial Adapter, Easy Mode Setting by Hidden DIP Switch


  • Adds one RS-422 or RS-485 serial port by connecting to a USB port

  • One DB9 male connector

  • No need to open chassis to set operation modes- upper case can be sliding open for easy RS-422, RS-485 mode settings

  • Installed as standard Windows COM port

  • RS-422 data signals: TxD-, TxD+, RxD+, RxD-, GND, RTS-, RTS+, CTS+, CTS-

  • RS-485 4-wire data signals: TxD-, TxD+, RxD+, RxD-

  • RS-485 2-wire data signals: Data-, Data+

  • Automatic transmit and receive control for 2-wire RS-485 half-duplex mode

  • Built-in termination and biasing

  • High speed serial port with the baud rate up to 921.6K bps

  • Non-standard baudrates supported

  • LEDs of Power, TxD and RxD for easy port monitoring and diagnostic

  • Serial port protected with surge protection of 10KV

  • Powered by USB port, no external power adapter required

  • Easy plug and play installation and RS-422/RS-485 device connection

  • COM port number assigned can be changed to any COM port number required

  • Works with USB 1.1 & 2.0 host port

  • Supports Windows 8, Windows 7, Vista, 2003, XP, 2000 and Linux

  • Supports Mac OS X 10.9 and above, This driver is signed by Apple


Compliance USB 1.0/1.1 compliant, USB 2.0 compatible
Speed 12 Mbps, full-speed USB
FIFO 128 byte transmit FIFO
384 receive FIFO
Serial Interface
Port Type RS-422/RS-485 selectable
Number of Ports 1
Connectors DB9 male
Serial Line Protection
ESD Protection 10KV
Serial Port Speed
Baudrate 300 bps to 921.6k bps
Serial Communication Parameters
Data Bits 5, 6, 7, 8
Stop Bits 1, 1.5, 2
Parity None, Even, Odd, Space, Mark
Flow Control RTS/CTS, XON/XOFF
Serial Signals
RS-422 TxD-(A), TxD+(B), RxD+(B), RxD-(A), GND, RTS-(A), RTS+(B), CTS+(B), CTS-(A)
RS-485-4 wire TxD-(A), TxD+(B), RxD+(B), RxD-(A), GND
RS-485-2 wire Data-(A), Data+(B), GND
Driver Support
OS Windows 7, Vista, 2003, XP (WHQL certified) and 2000
Linux Kernel 2.4 and up built-in support
Power Supply
Input Bus-powered
No external power adapter required
Chassis Plastic, ABS
Operating Temperature 0 to 55 °C (32 to 131 °F)
Operating Humidity 5 to 95% RH
Storage Temperature -20 to 75 °C (-4 to 167 °F)
Safety Approvals CE, FCC

RS-422 & RS-485 DB9 Male Connector Pin-outs
RS-422 DB9 Male

    RS-422 Signal Pin-outs of DB-9 Male

  Pin Signal  
  1 Tx- (A)  
  2 Tx+(B)  
  3 Rx+(B)  
  4 Rx- (A)  
  5 GND  
  6 RTS- (A)  
  7 RTS+(B)  
  8 CTS+(B)  
  9 CTS- (A)  
RS-485 DB9 Male

    RS-485 4-Wire (Full duplex) Signal Pin-outs of DB-9 Male Connector

  Pin Signal  
  1 Tx- (A)  
  2 Tx+(B)  
  3 Rx+(B)  
  4 Rx- (A)  
  5 GND  

    RS-485 2-Wire (Half duplex) Signal Pin-outs of DB-9 Male Connector

  Pin Signal  
  1 Data- (A)  
  2 Data+(B)  
  5 GND   

RS-422 Signal Wiring

    Point-to-Point 4 Wire Full Duplex

USB-COMi+2                                    RS-422 Device

    RS-422 with Handshaking

USB-COMi+2                                   RS-422 Device

RS-485 Signal Wiring

    Point-to-Point 4-Wire Full Duplex

USB-COMi+2                               RS-485 Device

    Multidrop RS-485 2-Wire Half-duplex

USB-COMi+2                               RS-485 Device