read ttl with NI9205can

[gustutu]

Hello,

I would like to read a TTL signal using a NI9205 ADC.I've tried different way but no success.

I'm looking for tracks.

Thank you

[GerdW]

Hi gustutu,

your 9205 module is able to read voltage signals, so you just read your TTL signal as voltage.

You should get values of <0.8V (LOW) and >2.4V (HIGH). To get boolean values you just compare your voltage signal with a threshold value of 2.0V…

[gustutu]

Ok but at the end i have a loop with a value wich is 0 or 1 but i have to detect the frequency of the signal.

[GerdW]

Hi gustutu,

but at the end i have a loop with a value wich is 0 or 1 but i have to detect the frequency of the signal.

Don't know what kind of loop you have and why you only have one (1) value of TRUE/FALSE.

Source code (aka an attached VI) would be helpful here…

You should read more samples with a higher samplerate - obey Nyquist when you want to determine frequencies!

[gustutu]

voila

[GerdW]

Hi gustutu,

so you read "one channel, one sample" and expect to determine frequencies from just one sample?

LabVIEW comes with alot of example VIs, just study them!

[gustutu]

i 'v already tried with this multisample but this ****** vi stop the programm if the signal is 0

[GerdW]

Hi gustutu,

what have you tried?

What is a 6-star VI?

Why should it stop when the signal is 0?