Topic: Vantage Pro 2 Diagnostic Screen

[Spud67]

I have a Vantage Pro 2 and recently created a ticket with Davis for the anemometer not reading wind speed accurately. I bought this unit new in December of 2021 and have replaced the outside temperature and humidity sensor under warranty. I hope I didn't get a lemon and have to replace the whole unit.

Looking at the diagnostic screen I found the values in position 1 and 2 on the console screen were not incrementing equally.
Position 1 indicated the number of times the anemometer reed switch was seen closed and position 2 indicated the number of time the anemometer reed switch was seen as open.

When I contacted Davis, the said that that indicated there is a problem with the reed switch and sent me a warranty replacement anemometer.

I installed the new anemometer and I don't see a difference the data in position 1 and 2 on the diagnostic screen. The number of times the reed switch is seen as open is a much higher number than the number of times the reed switch is seen as closed.

Each time the console receives a good packet the number is position 6 of the diagnostic screen increments by one. At the same time the number in position 2 (reed switch seen as open) increments by 1 but the number in position 1 (reed switch seen as closed) does not change.
In a one minute time frame with an average wind speed of 13km/h the number in position 2 incremented by 23 but the number in position 1 did not change.
I assume that the numbers in positions 1 and 2 should increment equally for the number of time the reed switch opens and closes.

What are others owners seeing on the diagnostic screens for data numbers for position 1 and 2? I would like to hear from others what they are experiencing with their Vantage Pro 2 and the anemometer data on the console.

To enter the diagnostic screen press and hold TEMP and then press HUM and release. In the top right corner displays the time and date, press the > to toggle between the time and date and the anemometer data. Position 1 is the time indicator and position 2 is the date indicator. To escape from the diagnostic screen, press DONE.

[johnd]

AFAIK Davis have never disclosed exactly how the ISS microcode works. The more obvious way of doing it might be for the speed circuit to generate interrupts and then count the interrupts in each speed window (eg 2.25sec). But the concept of contacts open/closed wouldn't really fit that idea AFAICS. Maybe the microcode just looks for resistance on that input at eg 5kHz or something. Since the contacts only open (or close - not sure which way round it is) briefly for each cups revolution, I'm not sure there's any reason that open and closed would be equal, and might be very different.

That's just me thinking out aloud - there may very well be more to it than that or a different mechanism altogether. But my point is that you need to know something about how the microcode works to have a real view about whether closed and open might not be very different numbers.

[Spud67]

AFAIK Davis have never disclosed exactly how the ISS microcode works. The more obvious way of doing it might be for the speed circuit to generate interrupts and then count the interrupts in each speed window (eg 2.25sec). But the concept of contacts open/closed wouldn't really fit that idea AFAICS. Maybe the microcode just looks for resistance on that input at eg 5kHz or something. Since the contacts only open (or close - not sure which way round it is) briefly for each cups revolution, I'm not sure there's any reason that open and closed would be equal, and might be very different.

That's just me thinking out aloud - there may very well be more to it than that or a different mechanism altogether. But my point is that you need to know something about how the microcode works to have a real view about whether closed and open might not be very different numbers.

Thanks johnd : this was also my thinking out load. I am not sure how the wind speed is communicated to the ISS. I just assumed it was an open and close of the reed switch similar to a relay. I know the wind direction is a resistive value from a potentiometer on the anemometer.

Thanks for the reply.

[Snowda]

On my VP2:
Pos 1: 162
Pos 2: 8074

Pos 1 didn't change while I was watching it (3-4 mins). Pos 2 seemed to increment by one with each xmission or about once every 3-5 seconds.

[Spud67]

On my VP2:
Pos 1: 162
Pos 2: 8074

Pos 1 didn't change while I was watching it (3-4 mins). Pos 2 seemed to increment by one with each xmission or about once every 3-5 seconds.

Thank you SnowDa, That is exactly what I was curious about. If others were experiencing the same thing as I am.
Good to see that it is probably normal.

[mcrossley]

I looked at these in the past and mine never increment in sync either.  Like John I'm not sure what these counts actually represent despite what the manual says.

[davidmc36]

""Note: All values with a * mark the value as being for Davis Instruments Internal use. All values with a ‡ mark values that are the same on both the Statistical and Reception Diagnostic screens.""

https://support.davisinstruments.com/article/jpddhzwlwu-console-diagnostic-mode

Seems they are nonsensical numbers to casual observer.

I am receiving two stations on my console. Only one is anemometer. Those numbers do not change when I toggle screens.

[Spud67]

I received this information from Davis Support and thought I would include it on my thread for others just in case they are curious about the anemometer readings on the diagnostic screen.

"The Diagnostic screen Open and Close of the Wind readings will show only one of those occurrences - either Open or Close, not both.  So, only one of those values will increment, the other will not."

Thank you Davis Support