Zip, here are a few things I need to mention/explain:
1) In linux terminal you should always start with "sudo su", provide the password and then run "mono AdvancedHMI.exe" or "mono GetSerial.exe" or "mono SerialToIPGUI.exe" or any other program
2) GetSerial.exe is a program I created to fetch all available serial ports by their friendly names (currently it works in MONO for Windows and Ubuntu linux). It is equivalent to "ls -l /dev/tty*" command mentioned on Debian page posted previously. Vitor's command "dmesg | grep -i tty" should show currently active serial ports.
3) I just tried running SerialToIPGUI program in MONO on Ubuntu linux and this program runs as well and lists all available serial ports. Its advantage is that it has graphical user interface and runs as either a Server or a Client connecting serial port to ethernet.
If Archie could provide an option within any driver to tunnel its packets through 127.0.0.1 then, by using the SerialToIP program, the Pi could be used as standalone option for HMI (if there is no other solution of course).
@Sprungmonkey
When I use DF1 driver alone in AHMI project and start it in MONO on Ubuntu, the attached exceptions occur and the AHMI screen closes.
Don't get any of that if using ModbusRTU or EthernetIPforPLCSLCMicro drivers.
Didn't get it with older version of AHMI either (v3.84) with DF1 driver.