Basic serial write and read, questions

[maple72]

Hi all

I have an external microcontroller connected to the PC using the serial port com 2, The microcontroller is porgrammed with its own instruction  langauge to recive a " A" character from the serial port , after that it will send a character "B" to the serial port

In the LabVIEW program I am doing , I have configured the serial port with the serial port specs of the microcontroller , when I write "A" to the serial port I am sending it to the "microcontroller " I am supposed to  read a "B" in return but it gives me a "AB"

cant get it

any ideas

Thanks alot

[Henrik_Volkers]

sounds like a 'hardware' echo  (any shortcut between pin 2/3?)

[Albert.Geven]

maybe the microcontroller is echoing what it receives before answering the question.
This was normal for a half duplex device.

imagine a display that displays all commands and data but has to get its information from the receiving serial line.

most of the time these controllers have a command to stop echoing or go in the full duplex mode.

[maple72]

Hi all

I have checked the same hardware connection , with the hyperterminal and the same setting , when I send an "A" it  returms for me back a "B", so I dont think the cause is the "Microcontroller " program

[Albert.Geven]

is your program maybe mixing it?

[maple72]

I will send you the program, wait