Testing the serial ports
You will need:
- The machine to be tested
- Crossover or "null modem" serial cable
- Connection to the internet
Connect the screen, keyboard and serial cable, then power the machine up. Log on to the desktop.
First, make sure that the
screenprogram is installed. Open a Terminal window and run the following commands.
sudo apt update
sudo apt install -y screen
Now open a second Terminal window.
Run one of the following commands in each of the terminal windows:
sudo screen /dev/ttyUSB0 19200
sudo screen /dev/ttyUSB1 19200
After running each command, the console will go blank with just a blinking cursor. Now run the following tests
- Click on the first terminal and type some text. It should appear in terminal 2
- Click on the second terminal and type some text. It should appear in terminal 1
If either of these tests fail, please double check the isolated port has been correctly installed.
Assuming both tests pass, simply close the terminal windows.