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Weather Station Hardware => Davis Instruments Weather Stations => Topic started by: johnd on June 18, 2020, 08:52:31 AM
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Edit: This post has been updated so that it now shows the latest iteration of the schematic rather than the first. The other older posts in the thread are no longer directly relevant. If you want to read more explanation and context then see: https://www.weatherstations.co.uk/pc_linkage.htm
With each new logger type that's launched it's getting increasingly tricky to explain to new users what role each type can fill. So I've concocted a schematic to try to help explain things but not sure how successful or complete it is. Any comments welcome. A few points:
* I've tried to keep it relatively simple so there's no attempt to include or name every individual logger type etc - just the mainstream ones;
* USB-type logger is shorthand for simple loggers, ie 6510USB and clones and indeed the serial logger;
* Enhanced loggers is just a convenient group term for WiFi Logger, Nano and the old WeatherlinkIP logger;
* I know weatherlink.com is in a sense just another cloud platform but it has a special prominence in the Davis ecosystem;
* This schematic focuses on VP2 wireless stations & also does not cover Davis remote stations like the Enviromonitor range or the Connect VP2 remote gateway;
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EDIT: The comments on this post are no longer relevant for the previous post because the above diagram has been updated with a newer diagram revision.
A great idea and nice diagram, but I think this sways the decision towards an enhanced logger as it seems to have all the options even though it has some cons. I think the current depiction you have under-represents the power of the WeatherLink Live and its API and the ability to support multiple local 3rd party software simultaneously. Whereas the enhanced logger only support but one software as long as you properly don't compromise the Loop 2 timing for the software to get data which means you really can't run more than one software reliably with the enhanced logger option. There is also no indication that the USB option would be limited to just one software.
Maybe see if you can represent this in version 2 of your nice diagram. ;)
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OK, many thanks. I'd like to keep it reasonably simple but try this - I've added a couple of short labels and varied the thickness of the connecting lines to give some indication of capability/utility.
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[tup] Perfect...nice elegant fix. For added clarity the WLL API support multiple programs on the same system or multiple systems.
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One more iteration then. (NB This image is on a transparent background - the contrast is actually a bit better against white rather than the grey of this page.)
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For completeness, perhaps "USB-type" could be clarified (includes serial-type, USB adapter, etc.)
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Version F:
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A further evolution (really needs to be accompanied by a few explanatory notes, but here's the graphic on its own):
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Ah, but the Weatherlink mobile app also talks direct to the WLL for real time data - when on the same LAN (and it hasn't "just stopped working"!) :lol:
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OK. I am trying hard for this not to become like a metabolic map (if you've ever seen one of those) - I'm sure I could continue to add details almost forever. But:
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To me it is starting to look like the NYC subway metro map. :lol:
Where does the Number 4 train stop?
Just kidding. I think it looks great. Nice job. I like seeing all the connectivity options and pros/cons. I don't think it is complicated if you take a moment to just take it one leg at a time. It is a lot more concise than any words could convey.
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Appreciate the schematics. I have had the VP2 for many years with the serial adapter as my work laptop had a docking station with a DB9 serial and was always on. But my gosh I finally disconnected the site as I was tired of rebooting my work machine due to the flakey driver crashing. Hind site is always better - I sure wish I had purchased the ethernet adapter but was suspicious as we had satellite internet and that was just as problematic as the serial adapter. Not to mention speed, quotas, etc.
We are retired now, off grid and more remote than ever and still on satellite (HughsNet G5). No internet interconnection. I've been looking into the ethernet adapter so a few questions:
1) Bandwidth with quotas. Is this a concern in the least? TX is one thing. Getting RX back of locally generated data to several devices is another multiple and frankly rather irritating. No, we can't/don't stream anything and still kill our 30GBs most months. Other than the standard use our only other IOT device is the Outback Power Mate3 console. They were supposedly looking a 3rd party integration at one time. Even if that happened it probably be cloud to cloud but I'm just guessing. But it sure would be cool to have a cloud app that displayed weather, UV, power generation, usage and warnings all on one interface. And history. Maybe I should write my elected (?) officials.
2) What is the right Davis device for the above considering the current state of things?
3) A bunch of other questions but they will arise out of inputs to the above.
Best, JRH
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Do you require to upload the weather data to a cloud service or do you want data available locally to yourself only?
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Do you require to upload the weather data to a cloud service or do you want data available locally to yourself only?
Ultimately I prefer the cloud. Not because of need to access the data remotely but because I have lost valuable history several times due to hardware failures. This happened twice in 6 years with weather data and more recently with the system monitor for our off-grid solar monitor. The cloud solves this. I have had the ISS and Pro 2 for around 15 years with nothing more than sending it in for a factory refresh in 2019 so I don't think I can complain about the cost to replace the USB adapter with the ethernet adapter. Davis has a good product and excellent customer service.
Getting back to my original post, how much data would the ethernet adapter use? I'm sure I can choose the intervals the ethernet adapter communicates. Several minutes is more than adequate for intervals as I hope the maximums and minimums of sensors would be updated. What about an upload of data if the internet goes out due to weather and then comes back online?
Thanks in advance.
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Great chart, thanks. I'm interesting in going down the WLL route, but not in paying the monthly subscription! Would be planning to upload historical data to a third party but left wondering what 'limited options' mean? Can I export all the historical data to be viewed through a third party?
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As it says, the chart is left relatively simple (!) in an attempt to avoid being too overwhelming. But the 'limited options' relates to uploads from the Davis weatherlink.com platform to other platforms. But at the moment this is limited to Weather Underground and CWOP. Davis do keep saying that further options are on the roadmap but so far it doesn't seem to be happening.
Bear in mind also that AFAIK it's only the current weather readings that are forwarded from wl.com to other platforms so any historical data would need to be generated by the third-party platform (although maybe the log of current readings eg every 15 minutes could be construed as historical data). But afraid I don't know whether CWOP or WU offers this option - possibly not.
TBH I think you have two main options:
1. Bite the bullet and get the Pro plan. I know this may be unattractive to some but it does work pretty well and is not that costly.
2. Run some other local software 24/7 that is compatible with WLL. One reasonably straightforward and inexpensive option here would be CumulusMX running on a Raspberry Pi, but there are other options too.
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Hey John,
A new version needed - add the AirLink ;)
Enjoy,
Paul
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The AirLink is a standalone thing. The diagram is about logger options and software connectivity. The only point I see in adding the AirLink is to show that it is standalone.
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2. Run some other local software 24/7 that is compatible with WLL. One reasonably straightforward and inexpensive option here would be CumulusMX running on a Raspberry Pi, but there are other options too.
Thanks for your reply. After a bit more reading, I think a Pi Zero W and CumulusMX might well be the best option for me.
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2. Run some other local software 24/7 that is compatible with WLL. One reasonably straightforward and inexpensive option here would be CumulusMX running on a Raspberry Pi, but there are other options too.
Thanks for your reply. After a bit more reading, I think a Pi Zero W and CumulusMX might well be the best option for me.
It was not really that hard to set up. Just speaking to the Pi and Cumulus portion.....data is console and metoepi
http://www.morewoodweather.ca/CumulusMX/gauges.htm
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Only had my WLL for 2 days, hence visiting the thread again....
I see one link missing.
The one where CMX reads from WeatherLink to catch up on data.
Still sitting on the fence at this point with regard to the required Paid subscription to get that catch up data.
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Still sitting on the fence at this point with regard to the required Paid subscription to get that catch up data
Hi Phil,
Presumably you have a free 30-day trial period...
My WL.com Pro subscription is expiring later in December and I will renew it. I've found it very reliable for CMX catch up, and able to view historical data and charts Plot Chart (weatherlink.com) (https://www.weatherlink.com/stripchart/plot/9e396562-3f54-435e-a363-34e63b9d35ec)
Enjoy,
Paul
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Presumably you have a free 30-day trial period...
I didn't until earlier today.
Will see how it pans out as to whether I stick with or not.
That said, one of my justification on expenses is "IT" Vs Beer.
On that basis, it's easy to justify a years subscription Vs a Week's liquid refreshments.
Very similar price.
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I see one link missing.
The one where CMX reads from WeatherLink to catch up on data.
As per the comment in my original post, I tried to keep the schematic relatively simple so as not to confuse new viewers (but not sure how successful that aim has been). There are several additional links and qualifications that could be added but that risk making the schematic less easy to understand. And this CMX catch-up feature falls into that basket I suspect.
But I'll certainly bear it in mind at the next revision.
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The WLL show a light gray line going to a PC. How is this connection achieved?
I have a WLL and a PC. In my current configuration the WLL communicates with my router and the data is sent to the Davis "cloud". From there I can download it to my PC. I would like to capture the data locally and skip the download step.
Thanks!!
Steve
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I don't have a WLL, so I'm not 100% sure. But I believe it goes like this.
Setup your WLL with a static IP in your router. That way it gets the same IP.
Second, you'll need some software like WeatherDisplay or CumulusMX on a PC. You'll use the IP address of the WLL to configure your software. I believe it uses port 2222.
You'll likely want to keep your software/PC running 24/7. I'm sure the WLL will have some memory in it to keep a few days worth of data to download later. But you'll only have a few days.
I'm sure someone will correct me if I'm wrong here...
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As @92merc says, CumulusMX uses the IP address to get live data from WLL whenever it is running. WLL sends the data to WL.com at the set interval and that logged data is used for archive catchup when CumulusMX is shut down, and then restarted. All that is needed is to select the Weatherlink Live station and do the Davis Weatherlink Live, including the API details, settings in CumulusMX.
You'll likely want to keep your software/PC running 24/7. I'm sure the WLL will have some memory in it to keep a few days worth of data to download later. But you'll only have a few days.
Not sure how much data WLL itself can store as it does an update to WL.com whenever it gets an internet connection but expect it is quite a long time. Recently I had a computer issue and restarted from a backup more than 30 days ago and CumulusMX got all the archive data from WL.com at the 5-minute interval.
Enjoy,
Paul
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The WLL show a light gray line going to a PC. How is this connection achieved?
There is no huge significance to the WLL line being grey. It is a thick solid line to indicate that it is perfectly usable for passing data to a PC program. WLL is a network device, so data is only passed to a PC via a network connection - either WiFi or Ethernet.
However, using a different colour denotes that the data format is completely different from the traditional Davis binary API/format and so can only be used with software that is explicitly compatible with WLL.
The data architecture also differs in other ways, eg with WLL there is no concept of summary or archive/historical data in the traditional Davis sense. AFAIK any catch-up process (eg if the logging program was offline or down for any reason) needs to retrieve the missing data using a Pro subscription at weatherlink.com, rather than from the WLL unit.
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The data architecture also differs in other ways, eg with WLL there is no concept of summary or archive/historical data in the traditional Davis sense. AFAIK any catch-up process (eg if the logging program was offline or down for any reason) needs to retrieve the missing data using a Pro subscription at weatherlink.com, rather than from the WLL unit.
WLL do have archive data concept, but only gets sent to weatherlink.com, it's kept in WLL when offline and deleted as soon as it's uploaded. Official local API don't expose it. A local simulation of the weatherlink.com connection can capture that data (plus some extra internal data too).
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WLL do have archive data concept, but only gets sent to weatherlink.com,
OK, let me be more specific. Unlike the traditional Davis data loggers, WLL has no concept of summary/archive data as a separate special data format where the summary is generated and stored within the logger. The catch-up process for data flowing from WLL to wl.com simply involves (AIUI) queuing of the standard real-time dat6a packets. But even these non-summary packets are not available to for local download AFAIK.
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OK, let me be more specific. Unlike the traditional Davis data loggers, WLL has no concept of summary/archive data as a separate special data format where the summary is generated and stored within the logger.
Yes, it does. WLL sends both archive and loop data to weatherlink.com during normal operation. When catching-up, it only sends the archive data for the missed period. Archive data is generated and stored within the logger. Archive period is configured through weatherlink.com web interface and it's configured into WLL. It sends archive data using this period.
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Yes, it does. WLL sends both archive and loop data to weatherlink.com during normal operation.
That's how the old loggers work. WLL is different AIUI. Look at the API documentation, which hints at in notes like this: 'Please be aware that the WeatherLink v2 API is not a one-to-one correlation with the v1 API. The focus of the v2 API is on the raw data from the weather station as it is reported to the WeatherLink.com service. The v1 API was more focused on mixing different kinds of data together to form a report.' WLL uses only the v2 API. The stream of 1-minute real-time records is what wl.com calculates its archive data from AIUI.
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That's how the old loggers work. WLL is different AIUI. Look at the API documentation,
I took another path: I looked into the traffic between WLL and weatherlink.com, analyzed it, decoded it and emulated the connection. I can confirm that both loop and archive data are present. I've been collecting archive packets successfully for a few months already (and catching-up every now and then).
Here is some code I wrote to be used in Weewx:
https://github.com/michael-slx/weewx-weatherlink-live/pull/22 (https://github.com/michael-slx/weewx-weatherlink-live/pull/22)
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@jav: OK, thanks, sounds like good work. Always willing to be proved wrong if there is concrete evidence to the contrary. Davis have obviously been keeping very quiet about this possibility.