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Diffstat (limited to 'contrib/ntp/html/pps.htm')
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diff --git a/contrib/ntp/html/pps.htm b/contrib/ntp/html/pps.htm index a002c1f..97850d7 100644 --- a/contrib/ntp/html/pps.htm +++ b/contrib/ntp/html/pps.htm @@ -1,18 +1,19 @@ -<HTML><HEAD><TITLE> +<html><head><title> Pulse-per-second (PPS) Signal Interfacing -</TITLE></HEAD><BODY><H3> +</title></head><body><h3> Pulse-per-second (PPS) Signal Interfacing -</H3><HR> +</h3><hr> -<P>Some radio clocks and related timekeeping gear have a pulse-per- -second (PPS) signal that can be used to discipline the local clock -oscillator to a high degree of precision, typically to the order less -than 20 <FONT FACE=Symbol>m</FONT>s in time and 0.01 PPM in frequency. -The PPS signal can be connected in either of two ways: via the data -leads of a serial port or via the modem control leads. Either way -requires conversion of the PPS signal, usually at TTL levels, to RS232 -levels, which can be done using a circuit such as described in the <A -HREF=gadget.htm>Gadget Box PPS Level Converter and CHU Modem</A> page. +<P>Some radio clocks and related timekeeping gear have a +pulse-per-second (PPS) signal that can be used to discipline the local +clock oscillator to a high degree of precision, typically to the order +less than 20 <font face=Symbol>m</font>s in time and 0.01 PPM in +frequency. The PPS signal can be connected in either of two ways: via +the data leads of a serial port or via the modem control leads. Either +way requires conversion of the PPS signal, usually at TTL levels, to +RS232 levels, which can be done using a circuit such as described in the +<A HREF=gadget.htm>Gadget Box PPS Level Converter and CHU Modem</A> +page. <P>The data leads interface requires regenerating the PPS pulse and converting to RS232 signal levels, so that the pulse looks like a |
