How to send only 1 byte hexa code using VISA send for every 500 ms?

[eddiechai2003]

Hello,

I would like to send only 1 byte of hexa code from LabVIEW to a external device using RS-232 (300bits/s, 8-bit data, no parity bit, no flow control) every 500 ms.

The TX pin on the computer should stay at logic 1 level once it finished transmitting the 1 byte of data and wait for 500 ms before transmitting again.

I build a test code below:

The "String 1" output will be connected to the write buffer of the VISA Send. (Please note that the code above doesn't include the delay of 500 ms that I mentioned. Just ignore that for a moment.)

Will this code work as what I described above? I tried it on my project, but I was receiving weird things on the device.

Do I convert the hexa code correctly?

And how the VISA Send transmits the string? Does it include other "unneccessary" strings with the hexa code that I want to send?

Any help will be appreciated.

Thanks. 

[Baji]

U converted to hexadecimal correctly but check the bytes.To which instrument u sending this data.Dont forget to put the delay inside the while loop otherwise its heats up ur processor.

http://forums.ni.com/ni/board/message?message.uid=921526#U921526

Message Edited by Baji on 06-09-2009 04:33 PM

[MikeS81 · Accepted solution]

Hi eddiechai...,

you'll get a string of length 2 so you have 2 byte. You should use the to U8 and the type cast function. (see the attached picture). You have to disable the termination character to get what you want.

Mike

[eddiechai2003]

Thanks MikeS81,

That is exactly what I want.