Multirate sampling on E series cards

[MIG]

Hi,

I am interested in doing multirate sampling on an E series DAQ card i.e. sampling different channels at different rates. Most of the advice in this forum suggests that the best way to do this is to sample all channels at the maximum rate and then throw away the unwanted data.

But this link suggests that it is possible for the DAQ card itself to sample different channels at different rates, without sampling all channels at the maximum rate:
http://zone.ni.com/devzone/cda/epd/p/id/4795

I've downloaded the example LabVIEW code and it seems to work, however my question is, how accurate is the timing of the sampling for each channel. i.e. are all the samples for a given channel exactly equally spaced in time, or is there some amount of jitter in the timing ?

Thanks,
M.

[tnek]

Hi MIG,

The time between each channel in the scan list will be evenly spaced. There will be some jitter based on the stability of the clock itself. This information can be found looking at the specification of the DAQ card that you are using. Additional information on base clock stability can be found here.

Regards,
Kent
Applications Engineer