"Unruh" <[email protected]> wrote in message news:ttqam.47651$db2.44...@edtnps83... [] > USB only has one data line. It cannot "do" a DCD line except as another > bit of serial data, interleaved with all the other serial data. > Ie, you are not going to get any good signals for an "interrupt". > > You definitely need either a real serial port with a true hardware line, > or a parallel port to get true interrupts.
Be that as it may, a GPS/PPS system working over USB provided better results (45 microseconds jitter) on my test PC than a 1Gb/s Ethernet card (110-140 microseconds jitter) on a 1Gb/s lightly loaded LAN talking to a stratum-1 server, so I would not say that USB is useless. David _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
