The AK-4XRS485 allows you to connect your PC to a network of RS485/422 devices. Every RS485/422 channel can be accessed as a normal serial port (es. COM1) or using the FTDI API (D2XX).

It is based on the powerful FTDI FT4232H High Speed USB device to get four RS485 channels.

The board has a jumper on each channel to select the 120 Ohm load terminator resistor. There is also a 128 bytes EEPROM to save custom parameters.

Drivers for any Windows version and Linux are provided free from the FTDI site.


  • USB high speed
  • Up to 4 RS485/RS422 channels
  • 256 kbps data rate
  • Up to 32 transceivers in RS485 mode
  • Up to 32 transceivers in RS422 mode
  • Selectable 120 ohm load resistor
  • No echo cancellation.
  • +/- 80V fault protection
  • +/- 12KV ESD protection
  • Libraries and drivers for Windows and Linux, by FTDI



What’s on board

AK-4XRS485 on board

  1. Power supply
  2. RS485/422 drivers
  3. RS485/422 channel 1 with independent terminator resistor selector
  4. RS485/422 channel 2 with independent terminator resistor selector
  5. RS485/422 channel 3 with independent terminator resistor selector
  6. RS485/422 channel 4 with independent terminator resistor selector
  7. FTDI FT4232M USB front end

Additional information

Weight 0.025 kg
Dimensions 35 × 18 × 14 mm


7 years 20 days ago

Good day, what is the minimum and maximum speed RS485 interface?
Does not standard transmission baudrate (7E1), or only standard (8N1)?
They will work driver with Raspberri Pi 2?

7 years 19 days ago

Hi. The PHY on this board supports max. speed up to 2.5Mb/s. It can transmit and receive with 7 or 8 bits, 1 or 2 stop bits, with or without parity.
There are drivers for ARM and Linux, so it should work with the RPI (


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AK-4XRS485 USB to RS485/422 Converter (RETIRED)

The AK-4XRS485 is an USB-to-RS485/422 converter.

This product is discontinued and this page is kept just as a reference. You can find a replacement here.


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