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


Compliance USB 2.0 full Speed, USB 1.1 compliant
Speed 12Mbps, full-speed USB
Connector USB type B
FIFO 512 bytes transmit and receive
Operating Systems Windows 2000 up to Windows 10
Windows Server 2000 up to 2018
Linux kernel 2.6
Mac X 10.3 to 10.9 and above
Installation The driver is already installed (Linux), or automatically downloading and installing device drivers after Device connection (Windows).
Serial Interface
Interface RS-232/422/485 configured by software
RS485 Termination and Polarization configured by software
Number of Ports 1, 2 or 4
Connector DB9 male and 5-pin terminal block
Max. Speed RS-232:up to 1Mbps RS-422/485:up to 3Mbps
RS-232 Signals DCD, RxD, TxD, DTR, GND, DSR, RTS, CTS, RI
RS-422 Signals TxD-, 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
Protection 15kV ESD protection for all signals
Serial Communication Parameters
Data Bits 7, 8
Parity None, Even, Odd, Mark, Space
Stop Bit 1, 2
Flow Control Hardware (RTS, CTS), XON/XOFF
Power Input Power supplied via USB connector
No external power needed
Casing SECC metal chassis with DIN rail bracket
Operating Temperature 0°C to 55°C (32°F to 131°F)
Storage Temperature -20°C to 75°C (-4°F to 167°F)
Operating Humidity 5% to 95% RH
Safety Approvals CE, FCC