On Sat, Aug 2, 2014 at 5:08 PM, Greg Hennessy <greg.hennessy at cox.net> wrote: > Well, I chose the Trible Accutime just to have access to a PPS Your Accutime does provide a TTL PPS signal (by the way, PPS capable GPS receivers are quite inexpensive and common these days) but USB isn't the right way to import the signal.