USB-COMi-M is a single-port USB to RS-232/RS-422/RS-485 converter with dual connectors of DB9 & terminal block for flexible serial connectivity in industrial applications. Not only is the adapter designed external power-free; it can also provide power output to external serial devices when the feature is needed.

USB-to-Industrial RS-232/RS-422/RS-485 Adapter

The USB-COMi-M USB to RS-232/422/485 adapter is a USB-to-serial adapter that adds one industrial RS-232, RS-422 or RS-485 port to your system. The adapter is designed with both DB9 male connector and 6-pin terminal blocks for flexible connectivity options. The operation mode of RS-232, RS-422 or RS-485 can be set conveniently via an external 4-pin DIP switch without the need to open the metal case. USB-COMi-M provides a unique and practical feature of supplying power output of 5V, 150mA from the terminal block to the serial device that requires power.

The USB-COMi-M supports automatic receive and transmit control in two-wire RS-485 mode. The adapter provides flexible termination and biasing options of built-in 120Ω termination resistors for TxD, RxD, CTS, and built-in 750Ω biasing resistor for TxD, RxD. Designed in a compact, compact metal housing with DIN rail brackets, the adapter is ideal for industrial applications. A variant model with 2kV DC optical isolation and 25kV ESD surge protection is also available.

Datasheet & User’s manual


USB-to-Industrial RS-422/RS-485 Adapter

The USB-COMi-TB USB to RS-422/485 adapter is one of our new products that adds one RS-422/485 port with a 5-pin terminal block connector to a PC. The DIP switch for RS-422 and RS-485 mode setting is designed inside the plastic housing that can be slided open conveniently. Termination and biasing options are built-in. In addition, 6 jumpers for enabling TxD/RxD, 120Ω termination resistors and RxD, TxD 750Ω biasing resistor are inside the unit. Users can set the operation mode easily by pushing down the upper case and sliding it to open for configuration.

The USB-COMi-TB supports 4 operation modes:



RS-422 4 wire with Handshaking
RS-485 Full Duplex (4 wire)
RS-485 Half Duplex (2 wire) with Echo
RS-485 Half Duplex (2 wire) without Echo

The adapter is designed with LED status indicators for power, TxD and RxD for easy port monitoring and diagnosis. The RS-422/RS-485 port is protected with 10kV ESD surge protection. The serial port supports 128 byte transmit and 384 byte receive buffer. In half-duplex two-wire RS-485 mode, the feature of automatic receive and transmit control is available.

Datasheet & User’s manual