Isolated USB-RS485 Converter V3

KMP USB RS485 Isolated Converter V3.0 3D

Thanks our KMP Isolated USB-RS485 Converter V3.0, now you will be able to have a communication with RS485 devices through the USB port on your computer. It will allow up to 128 devices to communicate through the same data line over a cable length of up to 1200m/4000ft. It is and the ultimate expansion that allows you connect to almost every legacy industrial system using serial connectivity such as industrial PLCs, controllers, drives and HMIs. The RS485 can be used to turn old industrial systems like industrial machinery, heating systems and conveyors into new IoT devices.

The converter is equipped with 2.75 kV of isolation and internal surge-protection on each data lines to protect the host computer and converter against high voltage spikes, as well as ground potential difference. A USB RS485 Isolated Converter V3.0 also features a high-speed 500 Kbps transmission rate, and supports various O.S. It Includes by RS485 line galvanically isolated power supplier.

KMP USB RS485 Isolated Converter V3.0 Top


  • USB interface: Fully compliant with V1.0, 2.0 specifications
  • Powered by: FTDI FT231X
  • Power supplies from USB port, no external power is needed
  • Power supply for RS485 line is galvanically isolated
  • Converter gets 1 COM port in the system when it is connected
  • Unique device ID number
  • Device supplied: pre-programmed with unique USB serial number
  • RS485 line protection: Against surge, short circuit, and voltage peak
  • Compatible with Modbus RTU/ASCII and DMX protocols
  • Up to 128 nodes in network configuration
  • TX/RX mode LED indicators
  • Plugable RS485 connector
  • Entire USB protocol handled on the converter. No USB specific firmware programming required
KMP USB RS485 Isolated Converter V3.0 RS485 Terminal


  • RS485 Data transfer rates: from 300 baud to 500 Kbaud
  • 512 byte receive buffer and 512 byte transmit buffer
  • Data Format: Asynchronous data with all common combination of bits, parity, stop.
  • UART interface support: for 7 or 8 data bits, 1 or 2 stop bits and odd / even / mark / space / no parity
  • Adjustable latency timer: 1 to 255 msec
  • Adjustable read and write timeouts: 0 to 10000 msec
  • Transmission distance: RS485 Up to 4000ft (1200M)
  • ESD Protection: 35 kV
  • Isolation voltage: 2.75 kV
  • Operating environment: -20 to 50° C
  • Storage temperature: -20 to 70° C
  • Humidity: 10-90% non-condensing.
  • Dimension: 86 mm X 43 mm X 20 mm
  • Weight: 37 g.
KMP USB RS485 Isolated Converter V3.0 USB B Connector
KMP USB RS485 Isolated Converter V3.0 Left-Back

How to connect the USB RS485
converter with an existing line

You can connect your KMP Isolated USB-RS485 Converter V3.0 direct to existing RS485 line (the line ends are terminated with resistors 120 Ohm and the line is powered). In this case you must use A, B and GND lines.

KMP USB RS485 Isolated Converter V3.0 connects with existing line

Connecting the Isolated USB-RS485

Converter with a new line

You can connect your KMP Isolated USB-RS485 Converter V3.0 at the beginning RS485 line. And you can power the RS485 line with converter. It include galvanically isolated DC-DC power converter. In this case you must use A, B, V+ and GND lines. Resistors R1* and R3* (are depending at the line [you might use 560 Ohm]) for powering and 2x 120 Ohm for termination line.

KMP USB RS485 Isolated Converter V3.0 new line