[time-nuts] NTP/1-PPS/RS232 question

[David J Taylor]

From: Hal Murray

> Yes, this is right.  But watch the polarity.  It is easy to get it wrong.
>  In RS-232 the controls pins are different from the data pins.

The reference implementation of ntpd can accept either polarity.

It's one of the fudge options.
=====================

Although, IIRC from discussions with Dave Hart, the Windows port can only 
accept the normal positive-going signal on the DCD line.  The devices I've 
tested all have positive going signals.  Pulse width is typically 100 or 200 
milliseconds, with a few receivers giving a much shorter pulse.

Cheers,
David
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