Topic: Why Do I Have Different Outside Temperatures on WLL and VP2 Console?

[syvalley]

Maybe someone can help me figure out what I'm missing here. I have a VP2 sensor suite in my back yard that seems to be sending two different 'outside temps', one to my WLL receiver-->weatherlink.com, and the other to my VP2 console.  There's no calibration present in the console or the WL.com settings.  They seem to ebb and flow a bit, maybe based on time of day, for instance they were about 10 degrees apart 3 hours ago, but seem to be matching up right now. 

Since there is only one outside temp thermometer (in the sensor suite), shouldn't WL.com and the console always show the same temp?  I understand why there are two different inside temps, but I cant get my head around why I would be seeing two different outside temps. 

Thanks for your time.

UPDATE:  An hour ago, I covered my ISS with a dark plastic bag. The Outside T/H on the console and WL.com at that time was 80°/42%.  Now, an hour later, the console is 84°/36% and WL.com is 91°/31.3.  Does this make sense to anyone??

Update II: WLL seemed to accurately and quickly reflect the outcome caused by placing a plastic bag over the ISS.  The temperature has shot up 15 degrees and the humidity has dropped 14% in 90 minutes while the console has barely moved. It would seem possible or likely that the two devices (the Davis 6100 and my VP2 Console) are tied to different ISS's, or that my console is just wanky.  I think mcrossley might be on to something, so I'll try to figure out how to change the transmitter ID's and see what comes of it. If that doesn't work, I'll reset the console.

Update III: Per mcrossley's suggestion, I changed the transmitter ID of the ISS to 3 and then changed my console and WLL to reflect the new ID.  As of this point, the two are tracking exactly the same for TEMP OUT, HUM OUT and THW INDEX.  Now I'll keep my fingers crossed that it doesn't go off the rails in the morning. 

Final Update:
As of this morning, all readings are tracking the same on both my WLL and my VP2 Console, TEMP OUT, HUM OUT and THW (HEAT) INDEX.  Thank you all for your time and guidance!

[mcrossley]

Is there another Davis station nearby and you are picking up two different transmitters?

[TraderGary]

The weatherlink.com update frequency is once a minute.
Internet response time can also be effected by the routing that your Internet connection uses.

The VP2 Console temperature updates directly from the ISS every 10 seconds.

If you have the Davis Weatherlink Live 6100, the app for both iOS and Android also updates temperature every 10 seconds.

[syvalley]

Is there another Davis station nearby and you are picking up two different transmitters?

Interesting idea, how would I know?  And everything seems to be lined up again at this point, Temp., THW Index and Outside Hum, but that could still be the outcome of another nearby station I suppose. Maybe I'll throw a garbage bag over the station and see if that sends the numbers in a different direction.  I don't know what direction, but it should be apparent if it's affecting my station.

Thanks!

[syvalley]

The weatherlink.com update frequency is once a minute.
Internet response time can also be effected by the routing that your Internet connection uses.

The VP2 Console temperature updates directly from the ISS every 10 seconds.

If you have the Davis Weatherlink Live 6100, the app for both iOS and Android also updates temperature every 10 seconds.

I'm not sure the additional networking delay could account for a 10 degree difference at a given moment, and if I refresh my WL.com web page, the "Last updated:" time is always current or just one minute behind.

I do have the 6100 and the app - I will check in with it the next time the discrepancies show up.

Thanks!

[TraderGary]

The weatherlink.com update frequency is once a minute.
Internet response time can also be effected by the routing that your Internet connection uses.

The VP2 Console temperature updates directly from the ISS every 10 seconds.

If you have the Davis Weatherlink Live 6100, the app for both iOS and Android also updates temperature every 10 seconds.

I'm not sure the additional networking delay could account for a 10 degree difference at a given moment, and if I refresh my WL.com web page, the "Last updated:" time is always current or just one minute behind.

I do have the 6100 and the app - I will check in with it the next time the discrepancies show up.

Thanks!

I learned very quickly not to depend on weatherlink.com for current accuracy. It's only close to being accurate once a minute. Add to that the lag from the Internet and the lag from the Davis servers. If I want to see what my VP2 is currently doing I never go to weatherlink.com. If I'm at my computer, I glance at my VP2 Console. If I'm away from my desk, and at home, I look at my Android app. If I'm away from home I look at Weather Underground as my Meteobridge Pro uploads to WU every 5 seconds.

By the way, you can set the display resolution on your phone app to 100.0 accuracy and see what your sensors are really doing. You will have your temperature to a tenth of a degree accuracy. Of course you can do the same with your VP2 Console.

[syvalley]

The weatherlink.com update frequency is once a minute.
Internet response time can also be effected by the routing that your Internet connection uses.

The VP2 Console temperature updates directly from the ISS every 10 seconds.

If you have the Davis Weatherlink Live 6100, the app for both iOS and Android also updates temperature every 10 seconds.

I'm not sure the additional networking delay could account for a 10 degree difference at a given moment, and if I refresh my WL.com web page, the "Last updated:" time is always current or just one minute behind.

I do have the 6100 and the app - I will check in with it the next time the discrepancies show up.

Thanks!

I learned very quickly not to depend on weatherlink.com for current accuracy. It's only close to being accurate once a minute. Add to that the lag from the Internet and the lag from the Davis servers. If I want to see what my VP2 is currently doing I never go to weatherlink.com. If I'm at my computer, I glance at my VP2 Console. If I'm away from my desk, and at home, I look at my Android app. If I'm away from home I look at Weather Underground as my Meteobridge Pro uploads to WU every 5 seconds.

Good points, I too rely on the console 95% of the time (it's right in front of me behind my desk), but what's getting under my skin a little is that WL.com reflects the data that's going into the record, my historical weather document.  When I look back at today a week, month or year from now, I'm going to see a temperature for 7:00AM that's potentially off (at least off compared to my console) by almost 10 degrees.

Which actually brings me to another point, I also suspect that it may be likely that the "TEMP OUT" on my console is the inaccurate one, not WL.com. I have two other thermometers outside, one on a wifi movement tag and the other on my AC condenser, and both of them track a lot closer to the WL.com temp than the console.

Brain twister!   

[mcrossley]

It's a bit of a faff, but changing the ISS transmitter id is one way to check.

You can change it temporarily and see if both the VP2 and WLL lose contact after a few minutes, or if one still receives data.

If both of them stop, then you can set the ISS id back to original again and look for other causes.

If it does reveal a problem with receiving from two different ISS, then you can set the VP2 and WLL to both receive from the new ISS id.

[CW2274]

The weatherlink.com update frequency is once a minute.
Internet response time can also be effected by the routing that your Internet connection uses.

The VP2 Console temperature updates directly from the ISS every 10 seconds.

If you have the Davis Weatherlink Live 6100, the app for both iOS and Android also updates temperature every 10 seconds.

I'm not sure the additional networking delay could account for a 10 degree difference at a given moment, and if I refresh my WL.com web page, the "Last updated:" time is always current or just one minute behind.

I do have the 6100 and the app - I will check in with it the next time the discrepancies show up.

Thanks!

I learned very quickly not to depend on weatherlink.com for current accuracy. It's only close to being accurate once a minute. Add to that the lag from the Internet and the lag from the Davis servers. If I want to see what my VP2 is currently doing I never go to weatherlink.com. If I'm at my computer, I glance at my VP2 Console. If I'm away from my desk, and at home, I look at my Android app. If I'm away from home I look at Weather Underground as my Meteobridge Pro uploads to WU every 5 seconds.

Which actually brings me to another point, I also suspect that it may be likely that the "TEMP OUT" on my console is the inaccurate one

If so, that'd be a first for me. With that, have you tried a console reset?

[syvalley]

See the update in my original post.  Does a reset still make sense?  Guess there's nowhere else to go at this point.

[CW2274]

Certainly worth a try. What's the bag for??

[syvalley]

Certainly worth a try. What's the bag for??

I wanted to track how both the WL.com and the console registered the change.  In an ideal world they would both head up or down to a similar degree, network delays notwithstanding, but the differences are so far off that it just doesn't make sense.  The console stabilized 45 minutes ago at T/H 84/36, while the weatherlink temp continues to climb and the humidity continues to drop to 93/30.

[syvalley]

It's a bit of a faff, but changing the ISS transmitter id is one way to check.

You can change it temporarily and see if both the VP2 and WLL lose contact after a few minutes, or if one still receives data.

If both of them stop, then you can set the ISS id back to original again and look for other causes.

If it does reveal a problem with receiving from two different ISS, then you can set the VP2 and WLL to both receive from the new ISS id.

Just saw read your response - great idea! Is this something I would need to set via dip switches on the ISS, and/or just in the Device Configuration on WLL and somewhere(??) on the console?

[mcrossley]

Just saw read your response - great idea! Is this something I would need to set via dip switches on the ISS, and/or just in the Device Configuration on WLL and somewhere(??) on the console?

Just change the dip switch in the ISS as a quick test. Both devices *should* lose reception after a few minutes.

[TraderGary]

The weatherlink.com update frequency is once a minute.
Internet response time can also be effected by the routing that your Internet connection uses.

The VP2 Console temperature updates directly from the ISS every 10 seconds.

If you have the Davis Weatherlink Live 6100, the app for both iOS and Android also updates temperature every 10 seconds.

I'm not sure the additional networking delay could account for a 10 degree difference at a given moment, and if I refresh my WL.com web page, the "Last updated:" time is always current or just one minute behind.

I do have the 6100 and the app - I will check in with it the next time the discrepancies show up.

Thanks!

I learned very quickly not to depend on weatherlink.com for current accuracy. It's only close to being accurate once a minute. Add to that the lag from the Internet and the lag from the Davis servers. If I want to see what my VP2 is currently doing I never go to weatherlink.com. If I'm at my computer, I glance at my VP2 Console. If I'm away from my desk, and at home, I look at my Android app. If I'm away from home I look at Weather Underground as my Meteobridge Pro uploads to WU every 5 seconds.

Good points, I too rely on the console 95% of the time (it's right in front of me behind my desk), but what's getting under my skin a little is that WL.com reflects the data that's going into the record, my historical weather document.  When I look back at today a week, month or year from now, I'm going to see a temperature for 7:00AM that's potentially off (at least off compared to my console) by almost 10 degrees.

Which actually brings me to another point, I also suspect that it may be likely that the "TEMP OUT" on my console is the inaccurate one, not WL.com. I have two other thermometers outside, one on a wifi movement tag and the other on my AC condenser, and both of them track a lot closer to the WL.com temp than the console.

Brain twister!   

The only calibrated thermometer I have is the one that came with my VP2 which was installed Aug 2020. So its the one I trust to be accurate.

Here's what's happening with your WLL. It gets its data directly from the ISS, exactly the same way as your VP2 Console gets its data directly from the ISS. The RF path is the same and the data is the same. What is uploaded to weatherlink.com every 5 minutes is exactly what you would have seen on your Console at the instant it was uploaded to weatherlink.com. The data at that instant is exactly the same. It's RF data sent by the ISS. It can be no different because it's exactly the same RF data coming from exactly the same place.

I only use my weatherlink.com app on my PC to look at my charts. I know my chart data from weatherlink.com is what came from my ISS every 5 minutes and I know it is accurate.

All you need to do is stop thinking that what you are seeing from weatherlink.com on your PC screen is current data. It isn't.

[syvalley]

The only calibrated thermometer I have is the one that came with my VP2 which was installed Aug 2020. So its the one I trust to be accurate.

Here's what's happening with your WLL. It gets its data directly from the ISS, exactly the same way as your VP2 Console gets its data directly from the ISS. The RF path is the same and the data is the same. What is uploaded to weatherlink.com every 5 minutes is exactly what you would have seen on your Console at the instant it was uploaded to weatherlink.com. The data at that instant is exactly the same. It's RF data sent by the ISS. It can be no different because it's exactly the same RF data coming from exactly the same place.

I only use my weatherlink.com app on my PC to look at my charts. I know my chart data from weatherlink.com is what came from my ISS every 5 minutes and I know it is accurate.

All you need to do is stop thinking that what you are seeing from weatherlink.com on your PC screen is current data. It isn't.

I think I might be approaching this with a different experience and expectation point of view from yours.  I've had this VP2 setup for ~a decade and have  been running this Davis 6100 along with the weatherlink account for over a year, and I have never seen a discrepancy between the .com numbers and my console numbers, especially to this degree, and that includes up-to-the-minute rain information. And with the exception of a new rain bucket hiccup, it has been dead-on accurate all the time.  If I look at the chart or raw data information for today, it is just plain wrong, and there is no time-shift because of data retrieval or network delay.  There is also no correlation between what WLL has recorded and what actually happened.  My experience has been that that the real-time display of WLL metrics along with the historical data has been accurate.  And my expectation is that there is a fixable problem going on - nothing out of the ordinary.  It is just puzzling because, as you say, and I totally agree,

It can be no different because it's exactly the same RF data coming from exactly the same place.

.  Thanks for taking the time to pitch in.

[Mattk]

Just to confirm, this is a "10 Degree" difference you are seeing? That is Ten (10) Degrees?

[syvalley]

Just to confirm, this is a "10 Degree" difference you are seeing? That is Ten (10) Degrees?

Yes, that is what I meant.  I am a terrible writer and a worse proofer. Thanks for catching it.

[TraderGary]

OK. That's new information! I thought I was typing to a new user.

At this point the only thing that could be happening is that you are getting information from two different Davis weather stations broadcasting on the same frequency. You might have a new neighbor! We have seen this happen several times on the forum. MCrossley suggested this possibility earlier.

The solution is to change the frequency your ISS is broadcasting on. You will also have to change the frequency (Station ID) of all your devices.

Consult your manual(s). That will give you a better explanation of what to do and how to do it than I can here.

[syvalley]

OK. That's new information! I thought I was typing to a new user.

At this point the only thing that could be happening is that you are getting information from two different Davis weather stations broadcasting on the same frequency. You might have a new neighbor! We have seen this happen several times on the forum. MCrossley suggested this possibility earlier.

The solution is to change the frequency your ISS is broadcasting on. You will also have to change the frequency (Station ID) of all your devices.

Consult your manual(s). That will give you a better explanation of what to do and how to do it than I can here.

Thanks Gary, done & done, and so far, so good!  I'll feel like I can put this one in my rear-view mirror when things are good in the morning.  Thanks again for your guidance.