This may sound like a dumb question, but I have not run across a good "plain English" description of low-pass. I completely understand low-pass filtering with regards to RF and AF. But when it comes to this stuff, I am unsure of what it means. I am under the impression that it is logically related to the process of low-pass filtering AF and RF but not necessarily physically related. By my thinking, it is a way of obtaining a general (but accurate) "reading" of some type of signal, without processing all the minutia. If someone could kindly point me to some "understandable" description of the process along with some simple examples I would be much appreciative. I am thinking that I have probably incorporated this process without "knowing" it. To me, this is like PID a fairly simple idea with a complex definition. Michael Brown Instant Net Solutions www.KillerPCs.net "In the land of the blind, he who has one eye is king" -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.