What is the interchannel delay for USB-6251? Is is fixed and/or measurable?

[Physeter]

I would like to know what is the interchannel delay when sampling 2 channels at 500 kHz each, with a USB-6251.
Is it fixed and/or can it be measured?
My ultimate goal is to compensate the interchannel delay by interpolating between samples (I'm using spline interpolation), and offset one channel with the delay, to "simulate" simultaneous sampling.

Thanks in advance for comments and/or suggestions...

[JamesC]

Hi Physeter,

For most E and M series devices we use interval sampling, utilising 2 clock signals a Scan Clock and a AI Convert Clock.
The AI Convert Clock tells the multiplexer to increment and the ADC to take a reading. So with the use of a DAQmx timing Property node, we can work out the interchannel delay for a given sample rate.

Please see the attached screenshot or the example code in LV 8.0 format.



Regards
JamesC
NIUK and Ireland


Message Edited by JamesC on 02-26-2008 04:01 PM

[ChrisR.]

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@Physeter wrote:
My ultimate goal is to compensate the interchannel delay by interpolating between samples (I'm using spline interpolation), and offset one channel with the delay, to "simulate" simultaneous sampling.

Thanks in advance for comments and/or suggestions...

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FYI, LV has some waveform alignment VIs available in the signal processing palette. Just search for "align waveforms."

Chris