Important Info for Davis VP USB data logger users and potential users

Brian, I really wouldn’t take it too personally - the programmers at Davis always seem to be hard to contact - by anyone. Davis isn’t Microsoft - they only have fairly limited programming resource and AIUI they’re under a lot of pressure at present with several projects and deadlines all fighting for attention (just like any other smaller business really). Work is tough for everyone nowadays and maybe time spent on goodwill, but which doesn’t help towards meeting corporate objectives, is being squeezed more now.

And USBX is only one approach to mitigating the USB dropout issue. As has often been said previously and as you’ve highlighted again, attention to eliminating or suppressing RFI whether mains-borne or through-space seemingly remains the most effective answer.

I have often felt that their programmers have to do their homework, get their braces on their teeth adjusted and in bed by 8 pm on a school night. They probably home that Sally Sue will take them to the prom.

In contrast, Windy, has a lot to do with his life, his kids, his job, and avoiding having to weed the garden, yet he turns out a lot in a little time frame. Davis just makes a nice instrument,their software hasn’t changed much over time. I do like their direct update for the VP2 when there needs to be something changed on the console.

However… I do use both and have sent them suggestions regarding Weatherlink and have always been told that they pass it on to the programmer. I think that person or persons are not a full time and hence the high school geekie kid type.

I am just setting up my new Davis and had trouble of disconnection emailed them and got the reply that is at the top of this page
Tried to buy a couple of clamps but unable to, but a couple of PC shops gave me some clamps from some cables that they where throwing away seems to have sorted the problem .Changing batteries would have been a hassle as I am using the cabled Davis

Received replacement for usb data logger yesterday. 24 hours on serial data logger and no lock ups. YEAH! Fingers crossed.

you can uncross the fingers
I recommend people to get a serial data logger and then a good quality USB to serial convertor if not serial port (I have always recommended that) (or a PCI serial card even)

OK, here is a cheap solution which works fine for me and I don’t have any crashes anymore.
You see the USB connection close to the station. This is the weak point. Davis shouldn’t split the cable but should have one cable going straight from the WS to the PC. I guess their designers were asleep at Uni while the subject was “Interferences”.

All you have to do is wrap the connection with Aluminium foil.
Also pull the power cable apart from the USB cable and don’t let them run too close side by side from the WS to the PC. Don’t wrap the power cable around the little pins inside the station as Davis recommends it.

Cheers

PS: Davis, if you need a hand with your stations and need some more tips and design solutions, you can contact me (and in return send my money back for the station I bought).
PPS: An additional component (eg. a Daytime Fan Aspirated Radiation Shield Kit or an UV-sensor) would do too.

So has anyone else tried the above solution? If so did it work? I’m giving it a shot now (usb has dumped about 5 times this week).

I think it sounds like a good solution

I recently bought a Davis VP & have experienced the same lock up problems. I have followed all the advice on this forum. Ferrites on the premium USB cable & the AC adaptor. I have also installed the latest drivers for the UART from Silicon Labs. I did notice that my cheap & nasty computer speakers locked the data logger within minutes so they have now gone in the bin. Everything is a lot better now but it still locks up after about 36 hours. The computer I am running is a two year old Dell Dimension with windows XP. Has anybody got any more ideas?

Rumour has it that Brian is going to come out with a version of WD that supports Davis USBXpress. Is this true & if so when?

even usbexpress mode has the same problem they have discovered (it was done to see if it got around the problem)
davis said they were going to update the dll to have support for that

the solution is to use a serial data logger instead, and then a good quality usb to serial adaptor

Thanks to scirocco for the tip about kitchen foil on the male/female USB connection. I’ll give it go & let you know how I get on.
Cheers, Simon

It is a question of the extent of the dropout problem though. All USB solutions suffer from the issue to some extent (and that includes using a serial logger with a serial-to-USB adapter - I’ve encountered at least a couple of verified instances where this has happened with a serial logger, though fortunately both cured by attention to the leads, ferrite cores, sources of RFI etc). USBX does sometimes perform acceptably where the standard VCP driver fails, so it is definitely a useful tool in this context.

I know that Davis did look at other USB chipsets, such as those used in some of the serial-to-USB adapters, but although some performed somewhat better than the SiLabs one it wasn’t by enough of a margin to make it worth switching the production process. But ultimately, if you have an environment where there’s a significant amount of RFI around, then no solution connecting via a USB port is guaranteed successful - USB just does seem inherently more sensitive to RFI than straight RS232 when used continuously 24/7. Fortunately, a better understanding of the role of RFI in causing the problem, more recent drivers etc have reduced the incidence of the problem considerably - just as well really since very few serial loggers are purchased nowadays - but obviously a few unlucky users still do see the dropouts.

Having put silver foil over the USB connection I was chuffed to bits when everything worked non stop for 3 whole days! Then bang, & back to where I was. #-o

I live really close to an electricity substation & have some pretty beefy power lines over the garden. Might this be part of the problem?

Hi,

I doubt the power station is an issue.
Make sure you have both the power cable and the USB cable as far apart as possible. Make also sure not to use their cheap USB cable but a good USB cable.
Make also sure not to wrap the cables around the little pins inside the station but isolate them already inside the station.

Cheers
Scirocco

Thanks for your helpfull suggestions Scirocco. I have tried everything you mentioned. Working in the electronics industry means I can get some fancy cables cheap. The USB cable I am using is double screened with ferrite’s fitted & 24 carat gold plated contacts!

I have now given up & having talked to my helpful supplier am going to swap out the USB data logger for a serial one.

Hi Slead,

I’m sorry it doesn’t work for you.
I never had a crash again since I did the changes.
Can you post a photo how it looks like with the changes?
Maybe I see something which is not correct.

Cheers

At the risk of cursing my weather station I am going to give an update. I tried the cheap solution above and so far all is working well. I separated the cables by as much as possible and added aluminum foil to the connection. My usb connection has not had a problem for almost 2 weeks now (w/in a couple days of a record). The only other time it lasted this long was when I left the continental United States for almost 2 weeks. Yeah, I thought leaving the mainland for Hawaii was the fix, but I ran out of money and had to come home, everything crashed w/in 2 days of my return.

Thanks for the advice and I’ll report when and if everything crashes again.

Hi Scirocco, Hopefully there is a picture attached of the current setup. Let me know what you think.


Envoy.JPG

Hi Simon,

Pull the 2 outgoing cables a bit further apart and don’t shield both cables together in the silver foil.
How far apart are the cables inside the station (which is different to mine)? Separate them there as far as possible too.

Hope that helps.

Cheers

I have now received the serial data logger & it’s installed & running. One thing I have noticed straight away is that I am no longer getting red data quality indicators. Any way it’s early days yet but cross fingers & hope for the best.