Basic question to continuous signals

Question

Hello.
Unfortunately
I got no answers of my questions after reading in help documents and articles.
Technical
details: Labview version 7.1; we want to receive signals from different channels
of a lock-in amplifier. We have a PCI 6220 and a a/d converter.
First of
all I had the error -50103, but I could solve it, when I put the two signals
together in one task. All in one the program runs, but I have some questions in
basics.
For
example: When I choose a number of samples per channel of 100 with a rate of 50
Hz the signals run not continuously. I see some information in the chart, then
a few seconds there is nothing and after that the signals go on. With a number
of samples per channel of 1500 the curve gets worse. But I want a continuous signal,
whatever number of samples per channel I choose. Is it generally possible that my
signals will be continuously/directly run in my chart? Maybe with arrays, but
if yes how could it work? It really seems to me, that “DAQ read” saves some
information in for example buffers and then shows it in a chart, then saves and
show and so on. But that’s not what I want.
Please can
anybody answer my questions?
Thank you
very much.

Answer 1

It's basic arithmetic. If you specify a sample rate of 50 samples per second and request 100 samples, then it will take 2 seconds for the board to acquire that number of samples and return them (100/50). If you request 1500 samples, it will take 30 seconds to return that number (1500/50). The samples you see in the chart are continuous but the update rate of the chart is determined by the ratio of the number of samples and the sample rate. You can specify a higher sample rate or specify a lower number of samples.