Getting hourly data without logger??

[graculus]

Why would you buy a WLIP if you didn't want to use the web upload? If it's just the ability to access over a network then using a serial WL and a serial port server could be a simpler and probably somewhat less exensive option. In fact if you don't have a network then why not just use a serial WL and a long cable?

[dalecoy]

Why would you buy a WLIP if you didn't want to use the web upload? If it's just the ability to access over a network then using a serial WL and a serial port server could be a simpler and probably somewhat less exensive option. In fact if you don't have a network then why not just use a serial WL and a long cable?

Two reasons might be:

A.  Every computer on your "home network" can use WeatherLink software to access the logger directly. 

B.  Given some minor requirements on the IP address*, you can access the logger from anywhere in the world that you can get an internet connection. 

* static IP address and/or port forwarding and/or a "remote ip address" service or....

[d_l]

It is very useful for us to know that connecting using just the MAC address is possible.  Thanks for doing that experiment.  Clearly, I was wrong in believing that an IP address would be required.

There have been assertions, elsewhere, that the WeatherLinkIP logger will not communicate with the WeatherLink software, unless it is currently able to communicate with (and send data to) the WeatherLink.com site.  That would be one other worry. I found those assertions a bit hard to understand.   Do you happen to know (or want to test) the truth of that assertion?

That ability to communicate with just using the MAC is a clever idea.  Even if someone installs it on a network without a functioning DHCP server, it will still work, albeit a little slower.  I'm pretty sure that I used capability that when I first installed mine because I use a static IP network.

If you look in one of my posts here: http://www.wxforum.net/index.php?topic=6074.15 you can see the WLIP's configuration screen.  There is an option on it to disable the uploads to weatherlink.com.  If you did that and it also stopped the WL software from downloading from the logger, it would make the WLIP pretty useless.  Why would Davis then include such an option if it made the WLIP useless? 

Due to switching problems on my network, I've had my WLIP out of touch with the weatherlink.com servers for several days.  The WLIP couldn't get to my router's DNS proxy before uploading the archive data. During this "outage", I had no problem with downloading data from the logger into WL. That is as close to disabling the uploads as I've tried.

[Zephirus]

I am not sure I fully followed all he comment on this post, but there is one other way to get data  if you have WLIP - you can just download it from the WL web page.  Also, one of the biggest assets to WLIP is I don't have to leave a PC on for the system to log data and post it to CWOP or WUG or any other website.  If you have the serial or USB logger, you must leave a PC running if you want to post data to a website.  If you don't want to post data to a website the logger you use (benefits) becomes less clear as to choice (my opinion). I would add when I started my station I had an USB logger, and it had a lot of logging hiccups.  

[Mark / Ohio]

....Two reasons might be:

A.  Every computer on your "home network" can use WeatherLink software to access the logger directly. 

B.  Given some minor requirements on the IP address*, you can access the logger from anywhere in the world that you can get an internet connection. 

* static IP address and/or port forwarding and/or a "remote ip address" service or....

Which of course both can also be done with a regular Serial or USB data logger by adding a computer (that could be quite small and low power) running VirtualVP. 

[johnd]

Just a couple of minor comments/qualifications:

Two reasons might be:

A.  Every computer on your "home network" can use WeatherLink software to access the logger directly. 

But not simultaneously - an important caveat. Remember that the console CPU remains single-tasking. You can actually make (what look like but aren't) multiple simultaenous connections to the WLIP but the process of data transfer very quickly falls apart.

B.  Given some minor requirements on the IP address*, you can access the logger from anywhere in the world that you can get an internet connection. 

Yes, provided you don't run into latency issues over very long distance links. I've seen Bulletin data going half way round the world from a WLIP, but typically it drops out with latency-related errors after a while. Davis are aware of this issue and AIUI it's on the wishlist for further WL development but not high up the priority list.

[DaculaWeather]

The only reason I see using the IP datalogger is if you don't have the time or knowledge to build a web site but you want your weather data on the internet.

I've never used the IP datalogger but it sounds like to me that you limit what you can do with the data, and, how you do it. Based on what I'm hearing compared to the IP DL, the USB and serial dataloggers (I have serial) allow you to actually "touch" the data and do creative things with it.

So if you go back to the original question, I would say use a USB or serial datalogger.

[johnd]

The only reason I see using the IP datalogger is if you don't have the time or knowledge to build a web site but you want your weather data on the internet.

That's one reason, sure. But another common one is for users who would like web data 24/7 but don't want a PC running 24/7. And a third is users who would like the connection to a PC across a pre-exisiting LAN (either cabled or WiFi) - WLIP is obviously not the only way of doing this but it's quite a convenient option. And, overall, simple flexibility is a further attraction - you can do essentially everything that you can do with a serial/USB logger and, as and when you might wish to take advantage of this feature, upload data to weatherlink.com (either to use the web-page presentation or to use as a staging post for your archive data).

And, I meant to add: even for users who are comfortable designing their websites, if you just want a simple, straightforward but live presentation of current/today's weather conditions then using the pages from weatherlink.com in an iframe on your own site is probably the easiest way of achieving this. See the top and bottom images on a (long) page from our website for an example:

http://www.weatherstations.co.uk/data_handling.htm

[DaculaWeather]

I understand, but for anyone that wants more than a simple way to view their data on the internet, it looks like to me the easiest, most flexible way to manipulate data is the serial or USB option. Not saying it can't be done the other way but...

[d_l]

It is very useful for us to know that connecting using just the MAC address is possible.  Thanks for doing that experiment.  Clearly, I was wrong in believing that an IP address would be required.

Well I was mistaken.  After an even more exhaustive test, a computer can't communicate (or even find!) a WLIP without an IP.  What was throwing me off before is that the WLIP's DHCP-assigned IP is retained by the batteries of the Envoy.  The WL software apparently is translating the MAC to the IP and using that "below the surface" so the end-user can't tell it is really happening.  A Wireshark packet snoop shows this. Once I removed the Envoy's batteries, the DHCP IP was erased, and the WLIP couldn't even be found by WL (I can't say if a static IP would be retained on battery removal).

So the bottom line is that the WLIP must be set up with an IP by some method such as John suggested before it can be used with a cable to just a computer.  Once set up the batteries in the attached receiver would keep it functional.

BTW, a cross over cable is definitely needed.

[dalecoy]

Is the following from http://www.weatherlink.com/faq.php#comlan related?  Or something else?

"I cannot communicate with my WeatherLinkIP over a local network.
There is a bug in the WeatherLinkIP firmware (v1.0.3 and earlier) that requires it to find a DNS (Domain Name Server) before it can proceed with its normal operation. If you do not have an always on broadband connection the WeatherLinkIP will get stuck in a loop looking for a DNS. You will be able to use "Find" successfully in the WeatherLink software. You will also be able to ping the device but no further communication will be allowed. The solution is to update the datalogger firmware with version 1.0.4 or later."

It's certainly a complex issue.

[d_l]

I can't say.  I wouldn't think that FAQ question was a problem as I have 1.07 on my WLIP.

Wireshark shows that the Find button broadcasts a UDP discovery packet on port 22222 and then the WLIP responds with its MAC and IP in a UDP packet.  After that apparently the WL software doesn't need the IP to be entered and is happy to just have the MAC entered to communicate with the WLIP.  Below the surface, WL is actually making use of the IP as shown by Wireshark.  I don't see why a DNS would be needed in this set up as it is not using an name address to access the WLIP.

[Zephirus]

I guess another point WLIP vs USB or serial is that running a PC 24/7 is not the best thought for A) energy consumption B) Machine maintenance C) Fire hazard (from running a PC 24/7) - I mean I have friends who do it but also a business I work with burned down from the same.  When I had my USB logger when I left the house or went on vacation I turned my PC off.  Given a choice WLIP seems hard to argue against in favor of the 24/7 way.  OK now all the USB/Serial guys can yell at me !

[SlowModem]

I guess another point WLIP vs USB or serial is that running a PC 24/7 is not the best thought

You've made some valid points.  However, if all you have is a desktop computer that connects to the internet via dialup, I don't think the WLIP will accomplish or save much.  Until broadband is everywhere, I don't think WLIP use will be as widespread as it could be.

[DaculaWeather]

I've managed networks of computers for 25 years. MANY of the computers ran 24/7, all of the servers ran 24/7. Not once did we have a fire, rarely did I have failure, and most certainly no more than the computers that were turned off and on all the time. Now that I think about it, those probably failed more often.

Yes, they're obviously consuming more energy than something that's turned off, but my computer is doing something all the time, my site wouldn't update without it being on. So for many people, 24/7 is the only option.

[Bushman]

Anyone know the current draw of the WLIP?  I'm betting that it and a router are about the same as my console and SS netbook.

[johnd]

Anyone know the current draw of the WLIP?  I'm betting that it and a router are about the same as my console and SS netbook.

Easiest place to look for all current draw info is the table in the (second edition = Vue details) 2009 Davis catalogue. WLIP draw = 100mA ish. So at 5V then that's 0.5W or so, ie probably around 3% of a typical netbook draw. For most people with even a small LAN, the router will be on 24/7 anyway. 'course, there are all sorts of individual circumstances but most people running a WLIP will be accessing some sort of broadband connection via a LAN and router.

[Bushman]

No way does my netbook draw 15 watts.  Somewhere I measured it and posted the current draw but darned if I can find them.

[johnd]

If it's a standard Atom-based netbook it'll draw 10-20W on average - hence 15W as a rough mean. (Ion-based ones are a bit higher - up to maybe 25-30W under load). If you look at something like a FitPC then you can get down towards 5W.

Here's a webpage at random showing measured netbook power draw:

http://hothardware.com/Articles/Lenovo-Ideapad-S10-Netbook/?page=6

Actually that estimate of 0.5W for the WLIP is the DC draw. The draw at the AC socket will be a bit higher. I don't have a good idea about the efficiency of the latest switching mains adapters that Davis now use, but let's say 50%. So on this basis the WLIP draw would increase to say 1W at the wall.

But I don't disagree with the general point that Atom-based PCs use so little power that's it's no longer really an issue. So many things around the average house/office are going to use tens and hundreds of watts, so having one extra 20W PC running 24/7 is pretty insignificant. (And I'll be very interested to see just how little power the new second-generation Atom 'Pinetrail' PCs use when they're released - Jan 10th is it?) However, many 'traditional' PCs can be using 200W or more, which isn't so trivial. So the general comparison of a WLIP against a typical PC is still valid.

[Bushman]

ah. Found it!  http://www.wxforum.net/index.php?topic=3197.msg24802#msg24802  Note that this is a very low power netbook - Atom based with SSHD.  Draws 2-4 watts in low power mode (screen off, no writes).  Even flat out at 12 watts with all on incl USB it is pretty amazing how low the draw is on these things.

And I agree with you  - no comparison for a std. PC versus WLIP