Serial Communication

[dphan128]

Hi,

I have a custom built board that connects to the PC serial port and talk to it thru hyper terminal OK. But when I used the "Basic serial write and read.vi" from LabVIEW examples to communicate with my board then I can't read back the data consistently where as the hyper terminal reads back data perfectly every time. I have made sure serial configuration is the same for both cases.

What else do I miss ? Please give me some ideas. Thanks

Dan 

[Dennis_Knutson]

A common mistake is to not send a termination character. Are you sending a \r\n (Carriage Retrun\Line Feed) at the end of your commands?

[dphan128]

Hi,

I do have \n\r at the end of my command. Does the oder of them matter ? \r\n or \n\r .

Thanks

Dan

[Dennis_Knutson]

It matters if the instrument is expecting them in a certain order. It's easy to check to see if it matters with your board by simply swapping the characters.

[dphan128]

Hi Dennis,
I did try with the \r\n order after reading your first response. And surely enough, it WORKED most of the time. Thanks a lot. You saved me a lot of troubleshooting hours.

Also thank you NI for having this discussion forum. You have saved people like me from a lot of headache!

Dan 

[Nandha]

could you send me the vi file

i am also trying to do the same thing

to imitate the hyper terminal

thanks.

[Tournifreak]

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@Nandha wrote:

could you send me the vi file

i am also trying to do the same thing

to imitate the hyper terminal

thanks.

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Hi - try this. I found it on this site a while back. I think I may have modified it slightly for my particular application but it's still pretty generic.

Jon.