USB-COMi-SI-M 1-port USB to serial adapter (RS232/422/485) with optical isolation with metal case




  • Adds a high speed RS-232/422/485 serial port by connecting to a USB port
  • 2000V DC optical isolation for all signals
  • DB9 male connector & 6-pin terminal block connector for optimal flexibility
  • SECC metal chassis with DIN rail bracket
  • Powered by USB port, no external power adapter required
  • LEDs indicate TxD and RxD for easy port monitoring and diagnosis
  • Installs as a standard Windows COM port
  • Automatic transmit and receive control for 2-wire RS-485 half-duplex mode
  • Built-in termination and biasing
  • Serial port protected with surge protection of 25kV
  • Easy plug and play installation and RS-422/485 device connection
  • High speed serial port with baud rate up to 921.6kbps
  • Supports Windows XP to 10, Server 2000 to Server 2016 (WHQL certified)
  • Supports Linux Kernel 2.4 and above
  • Supports Mac OS X 10.9 and above, driver signed by Apple




ComplianceUSB 1.0/1.1 compliant, USB 2.0 & 3.0 compatible
Speed12Mbps, full-speed USB
FIFO512 byte transmit
512 byte receive
Serial Interface
Number of Ports1
ConnectorDB9 male
6-pin terminal block
Max. Speed921.6kbps for transmit & receive

RS-232 Signals

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
Protection25kV ESD protection for all signals
2000V DC optical isolation for all signals
Serial Communication Parameters
Data Bits7, 8
ParityNone, odd, even, mark, space
Stop Bit1, 1.5, 2
Flow ControlHardware (RTS, CTS), XON/XOFF
Power InputPower supplied via USB (5V) 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
Ordering information
Part number       323011