[ntp:questions] GPS_NEMA, but high offset and jitter?

David J Taylor david-taylor at blueyonder.co.uk.invalid
Sat Feb 27 11:09:08 UTC 2010

"David Lord" <snews at lordynet.org> wrote in message 
news:7usc5dFhgcU1 at mid.individual.net...
> I mentioned radioclkd(2) both of which in debug mode
> display state of selected pin (dcd cts dsr or rng).
> radioclkd -s poll -d -v ttyS00:dcd
> This gives time at each pulse edge.
> I'm sure there are other programs that do a better job
> for debugging serial data.
> For serial data on Windows, I've captured serial output
> by  using second serial port and a two headed (9pin + 25pin
> at both ends) modem cable that splits the cable for you.
> David

Thanks for that, David.  I've used a similar cable that came with, IIRC, 

I was really thinking of a program with an LED-style display, emulating a 
breakout box, but showing what was on the serial port (control) pins, 
sampling at 50Hz or so.  It sounds as if something like this would be 
useful to answer the questions:

- is my DCD connection showing a PPS signal?

- does my USB connection, emulating a serial port over USB, also honour 
the DCD line?

I would knock something up if there were enough interest, but it would be 
a Windows program so of limited interest to the OP.


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