User wants to change the default mode (RS-232) on COM2 to RS-422 or RS-485.
Serial port COM2 can be configured for RS-232, RS-422, or RS-485 with auto flow control.
The default setting for COM2 is RS-232. Configuration of COM2 can be done in the BIOS settings:
- Enter BIOS by pressing DEL on the keyboard during PC start up
- Navigate to menu "Chipset -> SIO Configuration -> Serial port 2 Configuration"
- Select "Interface Mode" and set the mode that you need
- Save the changes, and exit BIOS
See attached document for more details.