Author Topic: Ajax 2nd basic question...  (Read 1992 times)

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Offline ncpilot

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Ajax 2nd basic question...
« on: September 11, 2007, 01:52:00 PM »
Help me clear something up...

Not sure for other weather stations, but on the Vantage, although it receives a packet of info every 2.5 seconds I believe, isn't it true that the only sensors that update that frequently are wind speed and direction? All the other sensors have intervals more towards a minute or more?

If so, then Ajax updates at 2-3 second intervals at most will only show wind changes? Same for real time Flash displays?
Wilmington, NC
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Offline saratogaWX

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Re: Ajax 2nd basic question...
« Reply #1 on: September 11, 2007, 03:46:36 PM »
I think you're correct  that the wind direction/speed update the most often on most stations.

I notice that with WD clientraw.txt updates, the temperature (humidity, dewpoint) also update more than once a minute with my Vantage Pro.

With the VWS AJAX/Weather Flash, the current data fields update pretty much like the WD clientraw.txt fields update .. the running average fields (and sometimes the hi/low/rate/rate-min/rate-max values) change with almost every update as they are recalculated.

With a non-VP station, the data values may be much slower in change, depending (as you say) on the update interval of the weather station itself.

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Offline carterlake

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Re: Ajax 2nd basic question...
« Reply #2 on: September 11, 2007, 07:58:03 PM »
I don't think you want the Ajax updating every 2 to 3 seconds... not sure the browser could keep up with it.... 6 seconds seems pretty good for the Davis.

But you're right though... only wind is what really gets updated that frequently.

Temperature and rainfall are updated every 10 to 12 seconds; wind speed and direction are updated every 2.5 to 3 seconds; humidity and barometric pressure are updated every minute.

The issue is one of where the data comes from... you can't update just part of the data every 2 seconds and the rest every 12 seconds... since it's all in the same data file.

Now, obviously if you have a wireless LaCrosse, you might want to change the update to every 20 seconds as stuff just doesn't update that often.

However, in the end, the data is very very small and really only makes  a little difference in bandwidth usage between 6 and 20 seconds.

Davis VP2 6153; Weather Display (LIVE w/ Ajax); Quickcam for Notebooks Pro; Boltek w/ Nexstorm; GRLevel3; live NOAA Radio