On 2012-01-10, David J Taylor <[email protected]> wrote: > "unruh" <[email protected]> wrote in message > news:eg%[email protected]... > [] >>> pulse over the length of line he talks about should be no problem at >>> all >>> (but a microsecond-wide pulse might). The timing PPS I've seen are in >>> the >>> tens of milliseconds wide. If there is overshoot, perhaps a capacitor >>> to >> >> Did you mean 10s of ns? The Sure width is about 5-10ns. at the card >> without any line attached. The line could certainly broaden that up to >> about 1us, but ms? >> Even the Garmin 18 is less than a usec. > > The width of the Sure pulse is 100 ms IIRC. The GPS 18x LVC is also 100 > milliseconds, but can be programmed. Were you thinking rise-time?
Yes, I was talking about the width of the pulse's rising edge. It is the risetime that is of first importance for timing. The length of the pulse only is important in how the serial port identifies interrupts ( and I guess the possibility of the pulse been smoothed to nothing if too short-- but that would show up in the rise time first) > > Cheers, > David > _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
