Can I and how do I increase Distance between the Console and PC?

[MervynG]

At the moment my VP2 wireless console is in my study about a yard (metre) away from my computer (iMac). I would like to record the inside temperature in my hall instead which is more variable and relevant  and is also where my heating system primary sensor is also located. This would be far more interesting and useful data than the 'managed' inside temperature of my study which varies only by a degree or so year in year out. I do not want to have my computer in the hall though. Currently I have the normal c3yard (metre) USB cable connecting console to computer.

Is there a way to:

a) put the console much (say 25yards [metres]) further from a computer and yet still have them 'talk' to one another?

or

b) record inside temperature separately and remotely from the console?

[whitenemesis]

From the Weatherlink manual, one can extend the USB cable up to a max 5m (16')


Or install a remote temp station?

http://www.skyview.co.uk/dept1/acatalog/DAV-6372_Wireless_Temperature_Station.html

[MervynG]

Thanks whitenemesis but I need more (25 metres) and wondered if anyone had a way

[whitenemesis]

Sorry I added an edit after you posted

How about the remote sensor station?

http://www.skyview.co.uk/dept1/acatalog/DAV-6372_Wireless_Temperature_Station.html

[DanS]

Wireless or cabled USB extenders possibly? I've never used them but sure someone on here can speak for them. http://www.kvms.com/Section/USB-Extenders-Single-Port.aspx

[tomcj2]

My console is about 50 feet from my computer.  I used Cat 5 telephone wire to join them.

[whitenemesis]

My console is about 50 feet from my computer.  I used Cat 5 telephone wire to join them.

Does that work with a USB connection??

[xykotik]

  For the price of those extenders, I think I would just buy a second console without a logger.

I'm watching clodely for a solution as well.  ANY USB extender I've tried, powered or otherwise (haven't tried any UTP/Cat5 converters) hasn't worked for me, and I only need to go about 15-feet.  I don't think it likes passing within 2-feet of my microwave oven.

[Bushman]

I've used USB extenders (USB 1.1) to 50 meters on vid cams and other devices.  They run between 8-30 bucks from places like Monoprice or Dealextreme.  Work well, but not sure if they would work to extend the cable to the console.  For  a few bucks it might be worth a try.

[dalecoy]

a) put the console much (say 25yards [metres]) further from a computer and yet still have them 'talk' to one another?

Presume you are thinking of running a wire from the console to the computer.

Depending on your preferences, and wiring constraints, the two ways would be (a) the Serial Logger; and (b) WeatherLinkIP.

[The serial logger can, of course, have a serial-to-USB converter at the computer.

Yes, there are technical ways to try to extend the range of your USB logger.  Those are all in the area of "might work, might not, works for some people, doesn't work for others..."

[MervynG]

Hi dalecoy

I have the existing USB cable connected in the same room as the computer right now its just that I would prefer to re-site the console away from where the computer is - by about as much as 50m in cable run (10m 'as the crow flies' through walls though).

I don't mind how they communicate cable, wireless, network, powerline adapters or whatever I just seek a greater distance between console and computer.

[MervynG]

whitenemesis

But a console is nearly £400 v £24.99 for a USB extender (Maplin A44HG) and I have a sensor (in the console) its just that its in the wrong place.

Dan S

Great idea; will try.

tomcj2

How via a USB extender or ...?

xykotik

Did you do this via a router or network cos the Maplin product (and others) won't work this way; only as a directly connected extension between the two devices (console & computer in this case).

Bushman

Going to try thanks. Just need to run some Cat6 cable and clip the ends on.

[dalecoy]

Hi dalecoy

I have the existing USB cable connected in the same room as the computer right now its just that I would prefer to re-site the console away from where the computer is - by about as much as 50m in cable run (10m 'as the crow flies' through walls though).

Yes, I understood that you currently have the USB logger and want to move the console some distance away from the computer.  We'll all be interested in what works or doesn't work for you.  The point being that you may have to try several suggestions that work for other people, and might work for you.

If you had understood this desire for separation earlier, you might have considered a different logger.

[johnd]

The issue is that if you want to view live weather data on a PC/Mac then you need to use a distance mechanism that offers high reliability and resistance eg to RFI. With data passing every couple of seconds, it doesn't take much of a glitch to hang the connection and even if that just happens once a day it can get very frustrating.

As dalecoy says, there are several technically-feasible options - most obviously USB extenders, though it does need to be a true USB extender and not eg just a powered hub - but most of these can't be _guaranteed_ a priori to give 100% reliability. The chances are that a USB extender or a USB-to-Ethernet device server and then a LAN connection to the PC/Mac will work OK but there's a finite probability of frustrating glitches.

I agree that a serial logger (with, if necessary, a serial-to-USB adapter at the PC/Mac) offers the most robust option, but if you've already got a USB logger then that's not where you're starting from.

[MervynG]

dalecoy

Trouble is I've undertaken major development work so its not the same house anymore!

Johnd

So the difference between a serial logger and a USB one is more than the desire by the manufacturer to fit a different plug on the end then? Why please is a serial logger more reliable? And if I had one I'd still be needing to transmit from the serial plug on the console over the increased distance and how would I do that? And as a Mac user I don't have one of those quaint serial ports so I'd be adding another device, a USB converter, into the equation and what would that do for the reliability? If a USB extender doesn't work, and I've had no problems I know of with USB, wouldn't I better off considering a WeatherlinkIP? Just plug an RJ45 plug/Cat6 cable into the console direct and put my computer anywhere? I've read conflicting reports about all types unfortunately.

[johnd]

Why please is a serial logger more reliable?

I think you'd need to be an experienced electronics engineer to answer that definitively. But FWIW my understanding is that the serial specification was designed for slow data speeds (which is irrelevant for weather data - the amount of data transferred per second is relatively tiny) but which could also allow quite robust (ie interference-resistant) signals and for cable lengths up to around 50 feet (or longer with boosters).

USB came in to accommodate the demand for much faster data rates, but which could only be achieved over relatively short cables and the data speed inevitably meant that the signals were more vulnerable to interference such as RFI.

But the practical experience is that serial loggers very rarely give any problems whereas USB loggers, for all their convenience, are less flexible and need to be pampered a little more.

If a USB extender doesn't work, and I've had no problems I know of with USB, wouldn't I better off with WeatherlinkIP?

The WLIP logger is an excellent solution if you don't want to use a local PC/Mac at all (ie just use the uploads to wl.com) or are happy to run Weatherlink for Windows. There are caveats with other software packages and the WLIP is not currently compatible with Macs at all, for instance.

[MervynG]

Thanks johnd I'll try a USB extender and see how I get on and report back. May even fire up an old pc and see what extra outputs arrive!

[johnd]

Thanks johnd I'll try a USB extender and see how I get on and report back.

Do be careful though with the extender you choose. Some of the extenders I've seen advertised don't have their own power supplies but are port-powered drawing current from the ports that they're attached to. This is no problem at the PC end but I've no idea what happens at the logger end.

To the best of my knowledge, the WL loggers are not designed to be able to supply _any_ USB port power and you might very possibly damage the logger trying. Now it may well be that the extenders are designed to only draw power from the PC end and one of the conductors in the long cable delivers power from the PC end to the adapter at the remote end - this may well be an implicit part of how USB works. But I just can't be sure - maybe someone else here knows for sure?

[dalecoy]

So the difference between a serial logger and a USB one is more than the desire by the manufacturer to fit a different plug on the end then? Why please is a serial logger more reliable? And if I had one I'd still be needing to transmit from the serial plug on the console over the increased distance and how would I do that?

You were asking for distance, so the question of relative reliability is not the correct question.

The USB specification limits the cable length at 3 or 5 meters (depending on USB speed).  USB is also not as forgiving of interference, etc.  Google for the technical reasons for the distance limitations, if you wish.

The RS-232 (serial) specification recommends limiting the cable length at 19.2 bps, to 7.6 meters.  RS-232 is also quite a bit more forgiving of interference and, in practice, at 19.2 bps, it is routine to go 20 meters, using just plain regular telephone wire.  So, extending it is not usually a big deal.  And if "extra hardware" extension is needed, there is cheaply-available hardware that will extend RS-232 to the other side of the earth, if you need that. 

Of course, if you only have USB at the computer, then a serial-to-USB converter is needed.  Yes, that's an extra piece of hardware.

So, I hope you can get your USB connection to work.  Perhaps without an extra piece of hardware?

[Sherwood Nash]

There will definitely be some noticeable USB power drop off, the longer the cable.

I used to take bird table close up photos, using a Canon G9 with a USB cable and remote software.

The live video feed obviously used more data than your logger will, but the max (non external powered) cable length I could use,
was 11 metres (5m + 5m + 1m) before the laptop and camera stopped 'talking'.


Mike

[dalecoy]

johnd said you need an explanation from an electrical engineer.  It happens that I am one (BSEE 1962) as well as having a MS in Computer Science, so let me take a crack at it.  Fair warning:  it's technical, and requires a bit of background that won't fit in this forum.

There will definitely be some noticeable USB power drop off, the longer the cable.

Your observation is correct, although it's not really power dropoff.  It's an issue of "transmission line propagation".

Here's some info quoted from usb.org - NOTE: I advise everybody to go on the the next reply now!

<quoting>
Cables and Long-Haul Solutions

1.   Why are there cable length limits, and what are they?

A:   The cable length was limited by a cable delay spec of 26ns to allow for reflections to settle at the transmitter before the next bit was sent. Since USB uses source termination and voltage-mode drivers, this has to be the case, otherwise reflections can pile up and blow the driver. This does not mean the line voltage has fully settled by the end of the bit; with worst-case undertermination. However, there's been enough damping by the end of the bit that the reflection amplitude has been reduced to manageable levels. The low speed cable length was limited to 18ns to keep transmission line effects from impacting low speed signals.

2.   I want to build a cable longer than 5 meters, why won't this work?

A:   Even if you violated the spec, it literally wouldn't get you very far. Assuming worst-case delay times, a full speed device at the bottom of 5 hubs and cables has a timeout margin of 280ps. Reducing this margin to 0ps would only give you an extra 5cm, which is hardly worth the trouble.

3.   What about using USB signal repeaters to make a cable longer than 5 meters?

A:   Don't bother. The best solution is self-powered hub with a fixed 10m cable that had a one-port bus powered hub in the middle. The maximum range will still have to deal with the timeout, so any out of spec tweaking of the terminations between the two hubs and the timing budget still won't yield more than 5cm of extra distance.
<End of quote>
Try http://www.usb.org/about/faq/ans5  for somewhat-less-technical details, and

http://www.usb.org/developers/usbfaq#sig2  for the more technical stuff.

We now return you to your regularly-scheduled discussion.

[Wx4U]

What about just adding a temp sensor? Take a look at look at this wx web site: http://patricknash.com/myweather/current.html
 
Patrick lives in South Arlington, TX. He has been concerned about the high attic temperatures in the attic and has done a lot to insulate it. He has an attic sensor and it is displayed on his web page. I am pretty sure it is a Davis sensor, but I don't known which one. Also, he is on Weatherunderground at: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KTXARLIN37

I think this might be the best way to solve your requirements.
Bob

[Sherwood Nash]

Attic: 77.0°F ? Does he have teenagers?



Mike

[whitenemesis]

whitenemesis

But a console is nearly £400 v £24.99 for a USB extender (Maplin A44HG) and I have a sensor (in the console) its just that its in the wrong place.

But I didn't suggest another console? My link was to the remote (wireless) temp station offered by Davis. OK it's ~£240, not cheap but it will definitely give you what you are asking for. And no connectivity issues.

http://www.skyview.co.uk/dept1/acatalog/DAV-6372_Wireless_Temperature_Station.html

[MervynG]

Sincere apologies whitenemesis, it was xykotik that suggested the additional console at £400; I just got my responses (for which I am grateful) mixed up.

Nevertheless the remote sensor is £230 when I have one in the console that is just in the wrong location.

So I am left with trying a USB extender which is a no cost option if it doesn't work as I have the Cat6 cable & RJ45 plugs and crimpers, or a UTP/Cat5 converter (what is that?)

dalecoy

Have re-read your reply and see that you were just rhetorically stating that you believed I would continue to seek to have a cable between computer and console as opposed to not appreciating that I had one  already. Sorry. However, I don't mind what the connection is as long as it is reliable and spans the distance - 10m direct but no cable route or 50m cable run.



johnd

A 'usb-to-Ethernet device server'? Please explain what one of these is. If it involves a server in the form of a computer hard drive near the console then that is what I am trying to avoid. All I want in my hall is the console (cable or not to a remote computer).

Also I need to seek out a powered USB extender. Can't see one at the moment. Can I ask where you see them please?

Wx4U  Thank you for the idea. It sounds and looks great. But aren't the additional sensors hundreds of pounds/dollars?