@ anthonys - You already have the program setup and working for the FEZ Cobra II, we need to get it working with the G120E Development System now. Before that though, we need to get serial debugging working on the G120E Development Board so you can write and debug the CDC application. Start by connecting MODE to 3.3V on the development board and then connect a USB cable to your computer and the port labelled “USB <-> Serial COM1” on the development board. A COM port will appear in the Device Manager, but it is not for CDC yet. Once that works will we can move on to the next step.
Thanks John, i think i have got it now…i am using a custom board soi cannot do it directly as suggested by i understand now.
I have a serial to USB adapter which i will connect to COM1 and this will allow me to do serial mode 
I’m i correct?
@ anthonys - That is correct. Connect a serial to USB adapter to COM1 on your custom board and you will then be able to debug and deploy over serial. That will allow CDC to use the USB interface.
I will be using CDC to test the UART devices connect to the G120E board in isolation. I have GUI desktop app to config a chip through comport so this will help me do this.
Is this the best practice to test a chip in isolation using serial interface? The pass through ability of CDC is a awesome feature! What do other people use this for?
OK…i have connected the RXD0\TXD0 to a FTDI adapter, put the G120E in serial mode.
I can see the com port.
But i see scrambled data in realterm. Only get data on reset(scrambled), but i have loop to resend Hello World
What is the baudrate i need to set RealTerm for?
@ anthonys - That adapter is for serial debugging, not for use by your application. You will select the serial debug transport and that COM port in your project properties. That allows you to debug. Then you can setup the CDC application over the USB port.
ok…i have connect my project to the G120E in serial mode by changing the transport to SERIAL…seems to be working fine.
OK…got it working…
Final question for this journey…any suggested code to create a serial pass through from device to computer com port?
Found this https://www.ghielectronics.com/community/codeshare/entry/386 but Math.Min not recognised?
System.Math.Min() is in the mscorlib assembly.
@ scardinale - thanks
I notice that some software i have to test a chip allows me to select a com port but it is only showing the USB Serial Port and not the CDC Serial port? Should i be able to see both?