Greetings:
I'm not aware of any stock cards that allow this function. However, is there any particular reason why over-scanning your "slower" channel/channels is a problem? You can always through out the extraneous data. I've always been of the opinion that it's better to HAVE the data than to WISH you had it! :=) I'd just set your card to scan at the rate necessary to collect your fastest channel, and let the slower channels just collect the extra data points.
Just a thought.
Eric
Eric P. Nichols
P.O. Box 56235
North Pole, AK 99705