[ntp:questions] best gps receiver for time synchronization

David J Taylor david-taylor at blueyonder.neither-this-bit.nor-this.co.uk
Tue Mar 10 18:18:21 UTC 2009


Unruh wrote:
[]
>> The newer "x" version appears to be a lot more sensitive, at the
>> expense of somewhat higher current consumption.  You can tell the
>> LVC version what sentences to send.  Better check the technical spec
>> to see what the USB one can be told to do:
>>  http://www.garmin.com/manuals/GPS18x_TechnicalSpecifications.pdf
>
> Unfortnately, the LVC is a serial port output, plus a PPS output. The
> USB
> version has no PPS output and is liable to have pretty bad timing
> (where good=usec).

.. which is why I suggested checking in the manual as to whether the 
output could be set to be a better determined length, which is what the OP 
requested.  It may be he /has/ to use USB.

By the way, while timing on USB may not be wonderful, I have an 
application receiving some 40GB per day over USB, in fairly small packets 
from a DVB satellite feed, and the buffering isn't that great (a few 
kilobytes, I believe).  Most often it's lossless, but it may be that the 
error-correction in the stream-to-file software does a good job!  <G>

Cheers,
David 




More information about the questions mailing list