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gregbradley
07-06-2011, 09:16 PM
I want to run my observatory from inside my house.

I believe I need the blue ethernet cable and run a program to be able to control the observatory computer from another computer inside.

The blue ethernet cable would have to have plugs both ends and be about 40 metres long.

Is this feasible and if so where do you get the cable from with plugs on it that long?

Greg.

The_bluester
07-06-2011, 09:23 PM
Not sure you would get a cable off the shelf that long, maybe try somewhere like Jaycar.

If not off the shelf any place like Jaycar or a decent PC shop (That builds PC's rather than just retailing them) should be able to make you one up to length. Stripping and crimping terminations on them is a pretty simple affair.

DavidTrap
07-06-2011, 09:31 PM
I think if your going computer to computer directly you'll need a crossover cable???

Anyone??

DT

h0ughy
07-06-2011, 09:34 PM
you are better off making up the cable and having a powered hub at either end to guarantee signal strength over that length. thats how i have the internet up the back from the house - about the same distance

mswhin63
07-06-2011, 09:40 PM
Better off running Wifi and use a wireless hub

gregbradley
07-06-2011, 09:48 PM
I get it, so you buy the cable and the plugs and strip and crimp the plugs on.





I'll keep that in mind if just a cable doesn't work.



I tried that and it doesn't seem to reach.

oosh
07-06-2011, 10:03 PM
Long cables can be found on ebay without a problem.

renormalised
07-06-2011, 10:35 PM
A Cat 5 cable doesn't need a powered hub or a booster station because it should be good for up to 100-200 metres without transmission loss. Over that and you need active hardware to keep the signal at full strength without loss of strength. Most of the loss is due to crosstalk between the segments of the cable and the possibility of some outside interference.

Best place to get lengths of Cat 5 cable that suit your needs would be Jaycar.

michaellxv
07-06-2011, 11:40 PM
100m is the specified limit for Ethernet although I have seen it working past that. If your running it at Gig don't push it.

For your run I would suggest you get solid core cable and put wall mounted sockets at each end. Then a short patch cable from the socket to your equipment. That way the normal wear and tear is not on your 40m run. A short patch is easier to replace.

Not sure if they still sell Cat5, you will probably get Cat5e or Cat6.

Most modern network interfaces will autosense so crossover is less relevant now. With the patch leads its easy to drop one in if you need it.

NOTE: Don't buy solid core cable and the crimp plugs, that combination won't work.
ALSO NOTE: Don't buy mulistrand cable and the wall sockets, that combination won't work either.

ChrisM
08-06-2011, 02:15 AM
Greg, I've run a couple of about 80 metre lengths of CAT 5 cable (from house to obs) and the network operates without any problems. The cable is buried in the same trench as the power cable (and HD poly water pipe) but segregated.

I agree with Michael re terminating in a wall socket, then using a short jumper cable.


Re supply, I called in to a local electrical distributer and they sold me the remains of largish drum of Cat 5. This mob also do data installations so I'm sure that they would have terminated the cables if I'd asked. You just need the right tool.

Chris

gregbradley
08-06-2011, 07:12 AM
Thanks for the very informative replies. Very helpful.
At the moment I walk out to my observatory about 5 or 6 times each clear night.
Great for the dog as he gets to play fetch but sometimes late at night it would be nice to
simply check or refocus and let it go. Sometimes you discover a cloud has messed things up
or the mount has stopped tracking at the meridian for a while and you lost an hour of imaging.

Greg.

mithrandir
08-06-2011, 07:15 AM
The spec is actually 90m of solid core between permanent sockets and 5m for stranded fly leads at each end. Beyond 90m you should use fibre, and that is not cheap.



All GigE interfaces must autosense. The standard requires it. Some 100Mb do but not all. I save myself all the effort by only using GigE switches to connect things.

You might get wireless to work with high gain antennas at each end, but cable is more reliable, and no end-user affordable wireless does Gig.

Barrykgerdes
08-06-2011, 07:48 AM
I have wireless and ethernet. The ethernet is about 40 metres only made from a 25 metre cat5 and three pieces of cat6. It is arranged with two wall outlets to feed the equipments and a the length of 25metres and a 5 metre extension in the roof joining the wall outlets.

Performance wise I get close to 1Gb on the ethernet but only about 100 Mb on wireless.

Barry

DavidTrap
08-06-2011, 08:15 AM
The reason why I mentioned crossover cable was that Greg mentioned just the blue cable and plugging two computers together - no network hub. Are the sockets in your average desktop or laptop capable of "powering" a 50m cable run and are they auto sense or does Greg need a hub as well?

I've gone the other way with all this and bought 20m of a special USB extension (that can run up to 56m). I was sitting inside my camper trailer on the weekend with the scope outside in the heavy dew. Yes they're expensive, but still cheaper than a second PC and networking. They run at full USB 2 speed and I'm driving my QSI, auto guider, mount and Robofocus from a distance.

DT

jenchris
08-06-2011, 09:00 AM
The tool can be bought at Dick smiths for putting on the ends.
The ends are about 3 dollars for 10 or something -
The cable can be got at any wholesale electrical outlet or decent computer shop
If you want the wiring sequence, I can send you a photo for net or crossover ends.
I used to make up networks and I never had a problem with power drop no matter how big the shop or business.
If you're at a loss and still can't find ends or tool, I can send them down to you from Gold Coast - I have some cable too, but I don't know how much unless I take it off the roll and measure it.
Letme know how long and I'll see if I can make it up for you

D link do an ethernet extender - works over 150 metres I think

Waxing_Gibbous
08-06-2011, 08:33 PM
"Middy's" sells them tho' I dunno if they are in NSW.
Home Hardware also.
Charged me 30 cents a meter!!!
OUTrageous! :D
Also, any Tandy's or Radio Shack type store should carry it.

gregbradley
08-06-2011, 11:13 PM
Thanks very much for your info and generous offer. I'll let you know how I go.



I haven't seen a Middys store here but the others yes.
Thanks for the info. Very helpful.

Greg.

g__day
09-06-2011, 11:49 AM
My suggestions, having run about 25m cat 6 cables to an observatory:

1. Run two cat 6 cables - inside PVC piping (to keep water out). If one ever dies you have a fall over with no hassles to dig around. If there is ever a connection fault that is hard to trace - hvaing a spare cable makes it quick to see if its the physical line, the network card - the TCP/IP stack being corrupted.

2. Inside your house - run the cables into a gigabit switch. You never know when you might wish to have more connections options - like if you add a NAS or two or just want to connect multiple desktops or laptops. The switch gives you options.

3. I like VNC server (astolab PC) and client (home PCs) as very decent control software for a remote PC.

Cheers, Matt

Jerous
13-06-2011, 01:16 PM
I got a 50m Cat6 cable a year or two back, I use it all the time. Should be fine to use as is, I never bothered putting a powered switch on it before and never had any hassles.

If it were me, I'd pick one up from MSY.com.au in Auburn, customer service is non existant but the price is right. ( no affiliation )

A-Power Pre-Made 10m /20m /30m /100m-Roll $6 /$12 /$15 /$40

Just remember 50m is the length of an Olympic swimming pool which is pretty big, I don't think I've ever needed more than 30m of it, max at a time.