PCI-6023E+Labwindows 4.0.1(Acquire 2 signals "simult.")

[marcuscine]

Hello,

I've a program to acquire 2 analogic signals(sinewaves 100Hz-10kHz) "simultaneously" and I know that exists a interchannel delay. The problem is: that delay is different each time I touch the button of ACQUISITION of my application. I think that could be something relationed with the samples, but I changed it several times and it doesn't work. If somebody can help me it would be great. Thank you

[Spencer S.]

Greetings,

How are you determining that your interchannel delay is changing each time you acquire? How much is it changing? Which functions are you using for your acquisition? This information will be helpful for troubleshooting.

Spencer S.

[marcuscine]

Because at the beginning, I acquired the same signal(1KHz sinewave(+/-1V)) in 2 channels(simult.) and each time the delay between channels was different,totally random(almost 0< delay < 1/4*period).The functions I use are: DAQ_Op and DAQ_Vscale. I've already used AI_Vread with a timer but it's valid only for frequencies < 100 Hz.

[Spencer S.]

Greetings,

The functions you are using are for single-channel operations. Thus, I am guessing that you are calling them once for each channel. For multi-channel operations, you should be using the SCAN functions. For example, you should be using SCAN_Op instead of DAQ_Op. I would suggest that you take a look at the example program SCANsingleBufSync.C. It installs with NI-DAQ and should demonstrate the program structure you will want to implement.

Good luck with your application.

Spencer S.