LABVIEW + Two or Three channels signal acquisitions using NI USB 6008

[Justin_Liu]

Hello, 

I try to using USB 6008 to simultaneously acquire two or three channels data, but USB 6008 has only one analog-to-digital converter. So I think I can using some shift register and clock control and take turns sampling with different channels,  also can do some interpolation during acquisition data for other channels. But I don't know how to realize it. now I realize one channel data acquisition data and write(attached vi), and two channel test (attached vi)only can one channel work since the only one ADC.

If somebody can teach me how to realize the two/three channels acquire data, even only alternate data acquisition. Thank you very much!

[crossrulz]

1. Just set up the task to read more channels.  The device will do everything else for you.

2. For the DAQmx Read, use the Multiple Channels->Multiple Channels->Array of Waveforms instance.

[Justin_Liu]

Hi  crossrulz,

Thank you very much! I try to do using your reply. I want to know what kind you using the waveform graph? Now I couldn't display it right!

Justin 

[Justin_Liu]

Hi crossrulz,

Thank you very much! Now the waveform graph can work, display two channel data (One channel is used for acquisition fluorescence signal, another channel is used for acquisition temperature signal, both is analog voltage signal), (1). but now I let the same square wave signal connection with ai0 and ai7, the waveform graph display signal ai7 is right, the ai0 a little down shift, I don't know why?

(2). I want to separate the two channel signal, because the temperature voltage signal need some operation processing (The voltage signal is converted to the corresponding temperature value), I don't know how to separate the two channels data?

(3) I want to write the two channel data into one Microsoft excel in two columns, I don't know how to realize it?

Thank you very much!

[BdogTheWatchdog]

Hi Justin,

1) What is your wiring setup? Alternatively, you can use the 'Index Array' function to select the waveform you want to alter, and add a constant to it to display the correct data.

2) As previously mentioned, you can use the 'Index Array' function on your 2D waveform to select the desired data, or just the 'Split Signals' VI

3) Double click your write to measurement file and under 'X Value (Time) Columns' select 'One column per channel'

Best,

BrandonN

Applications Engineer

National Instruments