Serial communication with WioTerminal


I want to develop serial communication tool with Wio Terminal & C#(.NETFrameWork)

look at serial monitor in Aruduino IDE , it seems that Wio Terminal & sensor can communicate.
(beause see seral value & uploding regulariy )

but I can’t proceed how to output serial data in csv format with C#
do you know why ??

looking at C#'s code

It’s same baudrate in Wio, same Port in it.
I can Perform exe & see console window (it means no wrong grammer in C#)
but no any text or value