Topic: Solar Sensors offline (help)

[WraxallDave]

Hi There,

I need help or suggestions for a fault with my Davis VP2 Plus Solar and UV sensors.

I have a wireless VP2 Plus with Solar and UV sensors and about two weeks ago the solar and UV readings went to "------" on the VP2 Console. (the console has a power supply and batteries.)

I have changed the ISS battery, that did not make any difference; showing up as 4.4 Volts and reception shows 98%.

The manual says try wiggling the cables to see if the readings come back, that did not work, and I even made sure the connectors in the ISS were clean. No luck.

If I reboot the VP2 console the Solar reading do not come back, but once they did come back hours after a console reboot, but the readings disappeared two days later. The VP2 Temperature/Humidity and Wind readings are all working fine. The solar readings have been offline now for exactly two weeks.

The VP2 console has the latest firmware as suggested by Davis, but as yet no readings.

I tried Davis support but haven't had a reply.

Is there anyone that has seen a problem like this and could suggest anything to try. I am not going to reboot the console every day.

Any help would be appreciated.   

Dave

[johnd]

It's always an odd fault when two separate ISS sensors misbehave at the same time while other sensors on the same transmitter carry on as normal. It's tricky to know from your description whether the fault is at the SIM board or console, though either is pretty unusual.

Is there any chance that you know someone else in your vicinity with a VP2 console that you could borrow briefly? If both consoles show the solar/UV data to be missing at the same time then it would point to the SIM board having developed a fault. How old is it? My best guess is that it is indeed a faulty SIM that needs replacing but, as I say, it's all rather odd.

Actually, one other possibility does occur to me, though perhaps equally unlikely. If someone else has recently installed a VP2 or Vue nearby (and with no solar/UV) then maybe the signal at the console is equally strong from both. Simple test is for you to switch transmitter channels to eg #2 or #3 and see if the problem disappears.

[WraxallDave]

Hi There,

and thank you for replying.

The VP2 is old, circa 2009 and I have a soil unit on #3. I did have the soil/moisture unit on #2 and Davis suggested changing that to another channel so it was moved to #3, that did not fix the solar problem.

The soil and solar readings have been working all year, but the solar problem has only shown up in the last month.

Dave

 

[johnd]

The VP2 is old, circa 2009 and I have a soil unit on #3. I did have the soil/moisture unit on #2 and Davis suggested changing that to another channel so it was moved to #3, that did not fix the solar problem.

Um, OK. But why would it fix the solar problem if the cause is another ISS also on #1 (I'm assuming that your ISS is on #1)? So move the ISS to another channel that you're not currently using eg #2 or #4, just as a test.

The soil and solar readings have been working all year, but the solar problem has only shown up in the last month.

Well, my suggestion was that maybe there's a new VP2 installation in your vicinity. (And did you mean 'UV and solar' rather than 'soil and solar'? You didn't mention soil previously.)

[WraxallDave]

Hi There,

My brother has a Davis Vue without Solar or UV. He lives about 150 metres away across the road from me and has had the Vue running for at least two years.

I will try changing the address of the VP2 ISS tomorrow and see what happens.

I have the Davis VP2Plus on channel #1
and a Davis Leaf/Moisture unit on channel #3.

Dave.

[WraxallDave]

Hi John,

I didn't get the chance on the weekend to do what I had planned to the Davis VP2 to get the Solar readings back.

Suddenly this morning the readings popped back, without me doing a thing.

Dave.

[johnd]

Suddenly this morning the readings popped back, without me doing a thing.

TBH that doesn't prove much. If you are getting 'interference' from another nearby station then it's typical for the correct transmitter reception to come and go. I think what happens is that the console tends to 'capture' a given transmitter and lock on to that one potentially for hours or days (assuming that the secondary signal is strong enough) until something happens to prompt a resynch. Then the console might well capture a different transmitter for reception until the process repeats.

[WraxallDave]

Hi John,

I have an RF Spectrum Analysers arriving today, I am going to get to the bottom of this if it is interference.

Dave.

[johnd]

I have an RF Spectrum Analysers arriving today, I am going to get to the bottom of this if it is interference.

TBH I'm not sure how much an Analyser will help. It's only likely to be interference in the sense of another Davis station (without solar/UV) transmitting in the vicinity and which your console sometimes locks on to. So you'd be looking for 2 separate signals in the 868.0 - 868.6MHz band, which I'm guessing you'll probably see given that your brother's Vue is only 150m away. But you won't easily tell which one your console is currently locked on to. The simple way of telling is just to switch your ISS and console to a different channel, as previously suggested.

[WraxallDave]

I plan to check for a signal, then switch my ISS off and see if we get the other signal.

Would that be a good plan?

Dave.

[johnd]

I plan to check for a signal, then switch my ISS off and see if we get the other signal.

Would that be a good plan?

Well I guess that would work. But why not just switch channels on your station - it's just so simple and quick (assuming you have easy access to the ISS) and might give you an immediate answer.