read internal clock daqmx

[ramses64]

Hi,

I'm reading datas on a PCI board (6259), and there is a signal which determines when aquire a data series. Doing this, I'm loosing the time information : the output waveform is wrong, because it says that there is a constant dt, whereas it's wrong.
I would like to create a counter on the internal clock of my board, and read its value each time I read datas. Is it possible ?
I've done this (see attached file), but there is an error with speed.
thanks for your help,
best regards,
vincent 
 

[Jeremy_M]

Hi Ramses64,

If I well understand what you want to do, you would like to make an analog input acquisition with an external signal as start trigger. Even if you make a finite or continuous acquisition, the data waveform “dt” is implicitly defined by the sample clock you chose so should be constant. May you explain more precisely why you said that it’s not constant? Is it an external clock?

Even if you want to build an edge counter, there are several examples in LabVIEW that should have the behavior you are looking for (in the example explorer: Hardware Input and Output/DAQmx/Counter measurements/Count Digital Events). The picture below is taken from an example and should help you in your project.

I advise you to revise you analog acquisition to verify the sample clock you are using.

Regards,