When setting up external communication with devices via RS232 on Window you need to know which COM port to send / receive commands on.

There are a couple of ways to find this:

1. Check the 'Device Manager' app on your Windows machine and check the ports under Ports (COM & LPT)

2. Check the embed application settings by opening the settings panel, entering the password and click on 'Settings'.

Then scroll down to the Serial/RS232 devices section and you'll see the available COM ports being used:

Once you've found the COM port for your device you can continue to setup your RS232 device.

Further reading: How to set up an RS232 connection with a Windows device and embed signage