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| author | Michael Brown <mbrown@fensystems.co.uk> | 2016-02-03 22:40:23 +0000 |
|---|---|---|
| committer | Eric S. Raymond <esr@thyrsus.com> | 2016-02-09 16:04:52 -0500 |
| commit | 6a94e2254d02bc4d9e1d7d4015204c32855e8316 (patch) | |
| tree | 4fd74d260c2abf9e58709e769a937e32ffad8778 /gpsd_json.xml | |
| parent | d019151fc5ce02cbaf4ae56556614d320eb80347 (diff) | |
| download | gpsd-6a94e2254d02bc4d9e1d7d4015204c32855e8316.tar.gz | |
Add concept of a GPS-disciplined oscillator
Signed-off-by: Michael Brown <mbrown@fensystems.co.uk>
Diffstat (limited to 'gpsd_json.xml')
| -rw-r--r-- | gpsd_json.xml | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/gpsd_json.xml b/gpsd_json.xml index 03d3cb59..46bcdc0b 100644 --- a/gpsd_json.xml +++ b/gpsd_json.xml @@ -1341,6 +1341,77 @@ limited to about 1 millisecond. seconds.</para> </varlistentry> <varlistentry> +<term>OSC</term> +<listitem> + +<para>This message reports the status of a GPS-disciplined oscillator +(GPSDO). The GPS PPS output (which has excellent long-term stability) +is typically used to discipline a local oscillator with much better +short-term stability (such as a rubidium atomic clock).</para> + +<para>An OSC object has the following elements:</para> + +<table frame="all" pgwide="0"><title>OSC object</title> +<tgroup cols="3" align="left" colsep="1" rowsep="1"> +<thead> +<row> + <entry>Name</entry> + <entry>Always?</entry> + <entry>Type</entry> + <entry>Description</entry> +</row> +</thead> +<tbody> +<row> + <entry>class</entry> + <entry>Yes</entry> + <entry>string</entry> + <entry>Fixed: "OSC"</entry> +</row> +<row> + <entry>device</entry> + <entry>Yes</entry> + <entry>string</entry> + <entry>Name of originating device.</entry> +</row> +<row> + <entry>running</entry> + <entry>Yes</entry> + <entry>boolean</entry> + <entry>If true, the oscillator is currently running. Oscillators may require warm-up time at start of day.</entry> +</row> +<row> + <entry>reference</entry> + <entry>Yes</entry> + <entry>boolean</entry> + <entry>If true, the oscillator is receiving a GPS PPS signal.</entry> +</row> +<row> + <entry>disciplined</entry> + <entry>Yes</entry> + <entry>boolean</entry> + <entry>If true, the GPS PPS signal is sufficiently stable and is being used to discipline the local oscillator.</entry> +</row> +<row> + <entry>delta</entry> + <entry>Yes</entry> + <entry>numeric</entry> + <entry>The time difference (in nanoseconds) between the GPS-disciplined oscillator PPS output pulse and the most recent GPS PPS input pulse.</entry> +</row> +</tbody> +</tgroup> +</table> + +<para>Here's an example:</para> + +<programlisting> +{"class":"OSC","running":true,"device":"/dev/ttyUSB0", + "reference":true,"disciplined":true,"delta":67} +</programlisting> +</listitem> +</varlistentry> + +<varlistentry> <term>?DEVICE</term> <listitem> |