Equipment / Observatory Automation

[OzDave]

I'm thinking about how I can get my equipment to be controllable remotely if I have it set up down the end of the garden, on the roof, or perhaps in an observatory one day.

What I want to be able to do is get things setup on "site" and then relax inside the house where the control PC will allow me to monitor and control what is going on etc.

What I'm thinking of doing is running a conduit of cables from the end of the garden (underground) and then into the house for hooking up to the computer. The question is, what will go into the conduit?

Presently I can see three main types of signal - USB, Firewire, and RS232. Oh and maybe some power would be good too!

It seems to me that it's possible (although not cheap) to buy various "extender" or "repeater" kit that will transport these signals over CAT-5 cable. Therefore, if I were to run several CAT-5 cables plus some power in the conduit, it should be possible to hook up all of the different equipment.

I'm wondering if anyone has done anything like this and would have any advice? e.g. suppose I get an RS232-over-CAT5 repeater setup, would that tend to induce latency so that I might send my mount a command, but it will take a while to get there?

Anyway, I'd be interested to hear if anyone has tried anything like this, or is maybe contemplating doing it.

Regards,

David

[George]

Simplest way would be connect everything up to a laptop on site, they connect to laptop via CAT5 via VNC or even windows remote desktop.

That would only require 2 cables, power (for the laptop if its a long session) and CAT5.

[OzDave]

Hmmm, yeah I guess I could get a netbook or something and do as you say. Probably the cost of a netbook would be cheaper than all the repeater gear.

However, I didn't really want to leave the computer outside all the time as its a seaside location and what with dew and salt in the air, might not be the best. Still, maybe an on site computer is the way to go, maybe just not a laptop. Perhaps I can find a more rugged outdoors-ish type chassis and hook everything to that and use it as the repeater in some way.

More thought required...

[FraserClarke]

Can you build a 'closed' chamber for the computer to keep it safer from the elements? You could maybe even just put it in a big plastic box and drill some holes through for the cables....

An onsite computer would be easier than bringing all the cables back to the house I reckon. Also useful if you want to do onsite debugging of hardware issues...

[pilkinn]

I've had exaclty the same issue rolling around in my mind. As most things are now USB and there's a 5m limit on USB cables I too am trying to find a solution. A (wired) USB extender seems a possibility as it uses a Cat5/6 cable. You can get extenders with multiple USB connections on the remote end and a single USB connected at the PC end. This therefore sounds like you could, at the remote end, connect the mount control (I'm using a EQMOD/USB box), an autoguider camera (e.g. webcam) and the main CCD imager to the remote box. The main concern is download speed and comms contention bewtween the devices. Any delay could cause problems e.g. autoguider camera has to stream images to the PC, the PC running the guide software (e.g. PHD) must then tell the mount to move. Taking images from the main CCD shouldn't be too much of a problem as I wouldn't be doing this constantly - only at the end of each exposure and I don't care if the autoguider gets behind slightly when this is happening. Given that I have a good beefy PC would it work!?

[yesyes]

I think I would also use an on-site computer and use Remote Desktop or VNC over an Ethernet/IP connection.

But don't put it into a sealed plastic box as suggested. The computer needs to "breathe" or it will overheat. You could make holes where the fans are in the case and put some filters over it, like a car air filter or one of these hoover filter pads or similar. These would probably require occasional cleaning.

I don't think I would run direct cables. Serial RS232 doesn't mind having long cables but USB does. Also, running the power cable along the other cables could cause problems (interference). It might be an even better idea just running a power cable and then use Home Plugs / PowerLine adapters to run Ethernet over the power cable.

[Chris Rowland]

I'd have a PC in the observatory. An older PC should have enough power to control the scope, do image acquisition, guiding etc.

You can control it using remote desktop or VNC over some sort of Ethernet link, it could be Ethernet or wifi. There are options to get longer range wifi using directional aerials.

Old PCs are remarkably resilient, but take care to have nothing on it that you can't bear to loose. I can't think of a reason to use a netbook.

There's a big difference between automation at the bottom of the garden and really remote automation where you can't get to the system in a few minutes to press a reset button or cycle the power.

Chris

[kev]

In my old observatory I used to use an olde desktop PC too. As you say very resilient, I used to drain water from in it occasionally!

As others have said, dont run the mains cable in the same trunking as the signal, as it will degrade it. (Many specs suggest min 6 inch away, in instore (retail) applications).

Also I used Screened cat5 to the obsy.

Kev

PS When you get the obsy PC running happy, ** image the disk **. Then when the inevitable occurs (and believe me it will), you wont have to reload a new disk from scratch, but just restore the image and update the anti-virus software.

[OzDave]

I think what I'm going to do is run a power line plus several CAT-5 runs. I have found that you can buy a USB-over-CAT-5 repeater/extender pair on Amazon for about £20. I think an RS232 extender can be had for a similar price. So, I will use a few of these to create some extended links for controlling all of my kit.

The only problem item I have is my Imaging Source camera, which is a Firewire device. I think I'm going to have to sell it and either get a USB camera, or one of the newer GigE ethernet cameras. I think I prefer the GigE route really as it'll be much easier to interface and no repeater devices needed.

So with cable runs like this, I won't need to worry about having a PC out in the field. Instead, what I intend to do is build myself a pier and have my cable run terminated in some kind of weather-proof wiring box alongside the pier. When I go to fit the scope onto the mount for a session, I'll just be able to plug in my device cables to the wiring box and hook up the other end back in the house to my control workstation.

I think I'll get one of those USB extender things off Amazon to check it will work properly and if so, that's definitely the route I'll be taking.

David

[yesyes]

Bear in mind that the cheap USB extenders are only USB1.1. USB2.0 extenders are a lot more expensive. There was a discussion about that on here recently...

[syd_malicious]

You could actually just get away with a single power cable. I have an observatory and can control everything from the house just via the mains. I then use my desktop to control via remote desktop.

You can get ethernet over power line such as this - there are a multitude and I got mine from fleabay.

This means that you just need one mains lead that supplies the power and the network.

The only points are

1) There are 85 and 200mbps varieties. The later are mainly for streaming video and I am happily using the lower speed variety.

2) There are 2 protocols - Homeplug and (I think) Powerline and they don't seem to be compatible

3) You cannot have a filter/surgeprotector that the adaptor plugs into as it filters out the signal

Other than this it works a treat and is much easier than the expense/hassle of running an extra ethernet cable.

As mentioned above do not even think of running USB etc from the garden to the house as it will be totally unreliable even if it does work.

Paul

[George]

I'd have a PC in the observatory. An older PC should have enough power to control the scope, do image acquisition, guiding etc.

You can control it using remote desktop or VNC over some sort of Ethernet link, it could be Ethernet or wifi. There are options to get longer range wifi using directional aerials.

Old PCs are remarkably resilient, but take care to have nothing on it that you can't bear to loose. I can't think of a reason to use a netbook.

There's a big difference between automation at the bottom of the garden and really remote automation where you can't get to the system in a few minutes to press a reset button or cycle the power.

Chris

If your going to have a PC in a unheated observatory either leave it running during the winter months or put some sort of low heating device in it (light bulb?) otherwise condensation will destroy the hard drives. Mine has happily run 24/7 during the cold months for the last 3 years down to -16C.

[GJBC]

usb extenders at dabs

Best Value 45M USB EXTENDER OVER CAT 5E (USB-BOOSTA) - dabs.com

we use them in the obs at Dyffryn works fine so far have not tried them over 10m yet though that will come later when we transmit to the screens and projectors we are looking to set up in another building 40m away

G

[Beyond_Vision]

The bog standard usb over ethernet connections will only work at less than a 5th of the speed of a USB 2.0 connection. So it will not perform as if the kit was plugged directly into the PC. This may cause issues when frames are being downloaded from larger CCD's and DSLR.

There are a few of us on here who have been waiting for Gigabit ethernet USB hubs to arrive in the UK. Another member on here has used a Silex 3000 device and reported that it seems to work ok. I then bought it but have had problems with it.

I decided to go back to using a PC local to the mount and using remote VNC software to control the outside PC. The PC is a 'Netopp' intel Atom Dual Core Processor with Nvidia ION graphics processor

Zotac ZBOX Atom D510 Nvidia ION Micro PC Free Delivery : Computers Net Top PCs : Maplin

This has now been reduced to £169 . This needs an operating system + harddrive and memory to be added. For £230-£240 pounds + cost of op system you could have a very small form factor PC running in an IP rated box.

Regards

Kevin

[pilkinn]

Kevin's idea of a small form factor PC got me thinking and I bought a little Samsung NetBook (£190). It's got 3 USB ports, Wireless-N and comes with WinXP (although I've upgraded it to Win7). So here's my set-up now...

Netbook running CdC ... connected via Hitec Astro EQDir adapter to my HEQ5 mount. I've just bought a wireless xbox controller so I will be able to control the mount using it during star alignment process, but for now I just use the ASCOM mount control panel via CdC.

My Starlight Express Lodestar autoguider on the guidescope connects to the Netbook via the second USB port. The autoguider lead from the Lodestar connects directly to the mount's guide port.

My main CCD camera on the main scope connects into the third USB port on the Netbook.

Using the Netbook and one of the image capture programs, focus both cameras. Then close the Netbook lid (changed the power settings on the Netbook to NOT switch anything off ever), throw a towel over it to stop it dewing-up or getting frosty then run in the house to keep warm.

Boot up my desktop PC in the house, remote desktop connect to the Netbook that is now visible on the network and viola ! I can control both camers and the mount from the comfort of the house.