USB to Serial RS232/422/485

The USB-COMi-PRO range is completely jumperless and free of DIP switches, all configuration is done by software. Just press the button and use the configuration program.

Serial ports on USB allow further use of existing devices, even when the computer doesn’t offer serial ports. Now the USB-COMi-PRO is extremely flexible in offered communication standards. Besides the classical RS232 and RS422 it offers three variants of the RS485 operation. The often required Termination and Polarization (BIAS) is also provided by built-in hardware, and it is controlled by the same configuration software.

The driver allows to configure the serial ports for bitrates of up to 3Mbit/s. In RS232 mode the bitrate is limited to 1 Mbit/s



  • Adds a high speed RS-232/422/485 serial port via USB connection
  • Serial operation mode and resistors can be easily changed by software
  • 512 bytes receive transmit buffer for high speed data throughput
  • Requires no IRQ, DMA, I/O port
  • RS-232 max bitrates up to 1Mbps
  • RS-422/485 max bitrates up to 12Mbps
  • Connector: one DB9 male connector one 5-pin terminal block connector
  • Auto transmit buffer control for 2-wire RS-485 half-duplex operation
  • Termination resistors installed on-board
  • RS-232 data signals: DCD, RxD, TxD, DTR, GND, DSR, RTS, CTS, RI
  • RS-422 data signals: Tx-, Tx+, Rx+, Rx-, GND, RTS-, RTS+, CTS+, CTS-
  • RS-485 data signals: Tx-, Tx+, Rx+, Rx- (4-wire), and data-, data+ (2-wire)
  • Monitor LEDs of TxD, RxD, Mode indicating port status
  • Easy operating mode configuration and setting
  • Virtual COM port drivers provided for Windows 10, 8.1, 8, 7, Vista, 2012, 2008, 2003, XP
  • Any serial device connected to USB-COMi PRO can be accessed and used by any client computers over network or across the Internet
  • Shares serial port between multiple computers from anyplace in the world  via Ethernet/WAN/VLAN/VPN/Internet


ComplianceUSB 2.0 full Speed, USB 1.1 compliant
Speed12Mbps, full-speed USB
ConnectorUSB type B
FIFO512 bytes transmit and receive
Operating SystemsWindows 2000 up to Windows 10
Windows Server 2000 up to 2018
Linux kernel 2.6
Mac X 10.3 to 10.9 and above
InstallationThe driver is already installed (Linux), or automatically downloading and installing device drivers after Device connection (Windows).
Serial Interface
InterfaceRS-232/422/485 configured by software
RS485 Termination and Polarization configured by software
Number of Ports1, 2 or 4
ConnectorDB9 male and 5-pin terminal block
Max. SpeedRS-232:up to 1Mbps RS-422/485:up to 3Mbps
RS-232 SignalsDCD, RxD, TxD, DTR, GND, DSR, RTS, CTS, RI
RS-422 SignalsTxD-, TxD+, RxD+, RxD-, GND, RTS-, RTS+, CTS+, CTS-
RS-485 Signals (4 wire)TxD-, TxD+, RxD+, RxD-, GND
RS-485 Signals (2 wire)Data-, Data+, GND
Protection15kV ESD protection for all signals
Serial Communication Parameters
Data Bits7, 8
ParityNone, Even, Odd, Mark, Space
Stop Bit1, 2
Flow ControlHardware (RTS, CTS), XON/XOFF
Power InputPower supplied via USB connector
No external power needed
CasingSECC metal chassis with DIN rail bracket
Operating Temperature0°C to 55°C (32°F to 131°F)
Storage Temperature-20°C to 75°C (-4°F to 167°F)
Operating Humidity5% to 95% RH
Safety ApprovalsCE, FCC