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Author Topic: Important Info for Davis VP USB data logger users and potential users  (Read 79678 times)

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Offline Scirocco

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #15 on: August 31, 2008, 12:09:51 AM »
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.
« Last Edit: August 31, 2008, 07:26:11 AM by scirocco »

Offline mstauss

  • Posts: 20
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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #16 on: October 31, 2008, 12:09:04 AM »
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).

Offline Weather Display

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #17 on: October 31, 2008, 02:18:54 AM »
I think it sounds like a good solution

Offline Slead

  • Posts: 17
  • Hungerford, Berks, UK
Re: Important Info for Davis VP USB data logger users and potential users
« Reply #18 on: October 31, 2008, 07:08:04 PM »
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?
Cheers,Simon

Offline Weather Display

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #19 on: October 31, 2008, 07:36:28 PM »
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

Offline Slead

  • Posts: 17
  • Hungerford, Berks, UK
Re: Important Info for Davis VP USB data logger users and potential users
« Reply #20 on: October 31, 2008, 07:37:57 PM »
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
Cheers,Simon

Offline prodata

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #21 on: October 31, 2008, 09:50:11 PM »
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

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.

John Dann
www.weatherstations.co.uk - UK Davis specialists
VP Knowledgebase Curator - see http://goo.gl/4p1gYQ

Offline Slead

  • Posts: 17
  • Hungerford, Berks, UK
Re: Important Info for Davis VP USB data logger users and potential users
« Reply #22 on: November 04, 2008, 07:29:05 PM »
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?
Cheers,Simon

Offline Scirocco

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #23 on: November 04, 2008, 09:37:20 PM »
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

Offline Slead

  • Posts: 17
  • Hungerford, Berks, UK
Re: Important Info for Davis VP USB data logger users and potential users
« Reply #24 on: November 12, 2008, 07:29:50 PM »
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.
Cheers,Simon

Offline Scirocco

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #25 on: November 12, 2008, 09:39:22 PM »
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

Offline mstauss

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #26 on: November 13, 2008, 05:00:08 AM »
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.

Offline Slead

  • Posts: 17
  • Hungerford, Berks, UK
Re: Important Info for Davis VP USB data logger users and potential users
« Reply #27 on: November 13, 2008, 07:25:50 PM »
Hi Scirocco, Hopefully there is a picture attached of the current setup. Let me know what you think.
Cheers,Simon

Offline Scirocco

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Re: Important Info for Davis VP USB data logger users and potential users
« Reply #28 on: November 13, 2008, 08:38:23 PM »
Hi Scirocco, Hopefully there is a picture attached of the current setup. Let me know what you think.

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

Offline Slead

  • Posts: 17
  • Hungerford, Berks, UK
Re: Important Info for Davis VP USB data logger users and potential users
« Reply #29 on: November 14, 2008, 08:31:07 PM »
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.
Cheers,Simon