Wind Instrument readings...

KBevo

Member
Eric, I have been testing my HB Wind Instrument using McSharry's 1Wire XAP software. Can you tell me what the calibration of rotation counts to mph should be specified? Couldn't find a number in the HB nor AAG documentation, but Michael's Xap documentation suggests 2 so I tried that, and then went to 1 but both result in unusually low mph readings for windspeed and windgust.

I have tested using a 30" fan that spends the wind cup rapidly but reads only 1 mph with either the 1 or 2 count/mph setting. Also, when polling, I almost always get a reading for Windgust, but the windspeed reading is returned very infrequently. Its that normal?

The wind direction reading seems right on.

Thanks
Gary
 

ericvic

Active Member
Gary,

I'm not sure exactly what McSharry's 1Wire XAP software is looking for but I'm assuming it wants to know how many counts per revolution. If that is the case the 2 is correct because there are two magnets in the Wind Instrument so the counter gets incremented twice for each time the cups go around.

The frequency of the readings is completely up to the software and if it is calculating a WindGust then I would figure that it would also be calculating the WindSpeed. You will need to ask Michael about that one.

Eric
 

KBevo

Member
ericvic said:
If that is the case the 2 is correct because there are two magnets in the Wind Instrument so the counter gets incremented twice for each time the cups go around.
I assume that is the number the software is looking for. Just wanted to be sure what the WI was supposed to deliver before going to Michael. Thanks. His documentation states "the defaults are 2 counts per mile per hour for wind speed", but obviously there must be some math behind the scenes to translate counts in a known time period to mph. If the WI does not deliver that time period in its readings, it is a mystery to me to know how the sofware could get it.

Is there other Xap software besides Michaels that supports reading of the WI via your Master Hub? I need to get a better feel for whether the problem is HW or SW (or just me <_< ).

Thanks
Gary
 

ericvic

Active Member
Gary,

Here is the actual formula Wind Speed (in miles per hour)=2.453*Vrotor( in revolutions per second) which I'm sure Michael already has in his software. The WI keeps up with the number of counts and the software knows how long it has been since it last read the counts.

I don't know of any other XAP 1-Wire software but you could run the free software for the WI available from AAG to verify your hardware.

Eric
 

KBevo

Member
ericvic said:
Here is the actual formula Wind Speed (in miles per hour)=2.453*Vrotor( in revolutions per second) which I'm sure Michael already has in his software. The WI keeps up with the number of counts and the software knows how long it has been since it last read the counts.
Thanks much Eric. With that formula, Windspeed seems to be an average of the speed over the polling period. The shorter the polling period, the closer to the "current" windspeed at the time of the reading. Currently I have Michael's SW set to poll every 5 minutes. I believe there is only one interval specification for polling all Master Hub channels, but is it possible for the SW to poll the devices on different channels at different intervals?

I don't know of any other XAP 1-Wire software but you could run the free software for the WI available from AAG to verify your hardware.

Ok.. I will find it. I assume it does not work with the Master Hub and will I need to connect it through a DS9490R-A.

Thanks
Gary
 

ericvic

Active Member
Gary,

I believe there is only one interval specification for polling all Master Hub channels, but is it possible for the SW to poll the devices on different channels at different intervals?
You can write software to poll each sensor at different intervals since each 1-Wire device has its own serial number and you can directly address that individual sensor. But most software that I know of only has 1 (or maybe a couple) of polling intervals so all the sensors get polled at the same time.

You are correct that shorter polling intervals will give you better wind speeds readings.

Ok.. I will find it. I assume it does not work with the Master Hub and will I need to connect it through a DS9490R-A.
I didn't think about that. You are probably right that is doesn't support a Hub :D
 
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