Quote Originally Posted by Andy_P
Maybe you could consider changing the Try..Catch arrangement to give you a more explicit error when it fails. At least change it to this for a test, so you know exactly what the exception is:
Code:
Catch ex As Exception
    Messagebox.Show(ex.Message)
I tried that and found out that I was trying to set the WriteBufferSize whilst the port was open, so I have closed it and re-opened before sending, and I can now set the buffer size!
So I shall test it on the machine today to find out if it has worked.

Also I have been testing another piece of software called DNC4U http://www.dnc4u.com/
With the following settings the program works perfectly at sending my files.


Here is an example of the files I am sending to the CNC (open in notepad or whatever)
http://www.mediafire.com/download.php?fe4zntyz91j