Testing with the RS422 to USB Cable

Owned by Farris Matar
Nov 12, 2022
2 min read

In order to test the RS422 breakout board, it needs to receive RS422 signals and then be measured to see if the outgoing single-ended signals match the input. To do so, there is a USB to RS422 converter cable available that allows us to send RS422 signals from any PC. The cable we purchased is the USB-RS422-WE-1800-BT from FTDI.

Using the RS422 to USB Cable with Windows 10

To use the cable with a Windows 10 computer, first download the required drivers from here. Follow the instructions from the installation guide to get the drivers insalled.

Once the drivers are installed, connect the USB to RS422 cable to your computer. The USB device should flash some LEDs to indicate it’s connected. Then go to your Device Manager and check which COM port it was connected to.

If you have multiple devices under the Ports category, right click each one and click Properties. The manufacturer for the correct device should be “FTDI”.

With the cable connected, open Command Prompt. By using the echo command, you can send signals to the USB and it will output the corresponding RS422 message to the orange and red jumper wires (orange is TX_P, red is TX_N).

Example: echo helloWorld > COM6 would send helloWorld to the USB to RS422 converter if it is connected to the COM6 port.