Multi-channel Continuous Analog Acquisition

[VEEDAY]

I see that there is a wonderful VI that demonstrates continuous acquisition of single channel AI. My question is whether it is possible to populate for multichannel? If yes, how to set and configure?

Please guide....

[GovBob]

Maybe read the following discussion. https://decibel.ni.com/content/thread/15688?tstart=90

[VEEDAY]

I have Arduino Mega 2650- I do not want a simple multichannel analog read. Its really slow (not good for detecting single above 5 Hz). I looked at demo VI in the LIFA for continuous analog acquisition which is really fast. I want example on those line.

[Kristoff2]

Hey RYADAV,

LINX (the succesor to LIFA) is probably a bit faster at multichannel sampling, however neither toolkit is built for super fast sampling.  The main goal of LIFA and LINX is to be easy to use and use follow standard LabVIEW programming practices.

How fast do you need to sample?  If its over a few hundred Hz you should consider myRIO or myDAQ.

Thanks!

-Sam K

LabVIEW Hacker

Join / Follow the LabVIEW Hacker Group on google+

[VEEDAY]

Thanks Sammy. Here is what I did. I used a simple while loop to read mulitchannel AI and plotted them in LABVIEW. According to manual, I can sample one AI read at 100 us, meaning 10 KHz is fastest for one channel. Now reading 5 channels means, 2 KHz per channel. This is not what I see. I am OK to read data at 1 KHz but how can we do. Thats the question. An example you can make for me?????

RY

[Kristoff2]

Where did you read that you can sample 1 analog channel at 100uS / sample?

There are many factors but with LINX using chipKIT you can sample as many channels as you have at ~350Hz using USB / Serial or ~1KHz using Etherent.  Like I said, there are many factors invovled but that is the ballpark you can expect.

How fast do you need to sample?

-Sam K

LabVIEW Hacker

Join / Follow the LabVIEW Hacker Group on google+

[VEEDAY]

On the Arduino AnalogRead page it says this http://arduino.cc/en/Reference/analogRead

[Kristoff2]

Right, so the 100uS number comes from code running on the Arduino.  Each time you call the Analog Read VI a packet is sent to the Arduino telling it to sample, it samples, and a packet is sent back containing the value.  This is how we get the data into LabVIEW and the transfers to and from the Arduino eat up a significant amount of time.  There are many ways to get data from the Arduino faster for example by creating your own arduino firmware that samples as fast as it can, buffers data and sends it back to LabVIEW.  A single purpose design like this can be faster, but does not provide a general purpose solution like LIFA or LINX.

-Sam K

LabVIEW Hacker

Join / Follow the LabVIEW Hacker Group on google+