Hardware Options for Remote Telescope ControlThis page tries to address the issues related to controlling an off-the-shelf "goto" telescope and CCD camera/focuser/filter wheel/field rotator, etc. remotely. This page is not intended for those doing visual observing per se. Remote is defined here as controlling a telescope and CCD camera (and other accessories) at a distance of more than about 30 feet (9 m) and less than 150.
The remote software control is dictated by the physical hardware connections. The hardware discussed will be pretty generic, trying to cover as many setup options as possible. Where applicable, information about specific makes/models of hardware is also provided.
My list in order of personal preference and performance are:
This order is based on my personal experience over many years of remote imaging. For the last 13+ years I have been remotely controlling "goto" telescopes either located in my backyard or on the road at star parties and over the Internet logging hundreds of hours of remote Internet telescope control using the Internet. This includes complete TPoint mapping remotely and often times complete recovery of remote systems that have failed for one reason or another (power loss, operator error, and so on).
In fact there have been times when I was remotely controlling a Paramount GT-1100S in Chile, a 24-inch telescope located on Mt. Wilson, and another Paramount GT-1100S also located on Mt. Wilson, all from one PC at the same time over the Internet while snow fell outside my house in Golden Colorado! Please see the detailed paper on Remote Telescope Imaging. This document has many details on the requirements for remotely controlling hardware.
Let's walk before running!
First let's take a very simple case. You have a desktop PC, Laptop, Tablet PC, or Pocket PC that you want to have control the telescope. Hardwired Direct ConnectionThere is simply no substitute for having a hardware connection from the primary computer to all of the hardware devices at the scope whenever/wherever possible. The principle reasons are performance, cost, ease of use, and hardware maintenance.
Wireless connections can be very convenient, but they are slow in performance compared to a direct connection, even with today's best and most expensive wireless hardware. Additionally, the size of the CCD detectors has grown tremendously over the years; downloading 3 to 100 megabyte files over a wireless connection is painfully slow.
Even using Remote Desktop/PCAnywhere, VNC, and all other remote control software that is completely bandwidth dependent fails in comparison to a simple direct connection. Yes, remote software has come a long way, but no remote control software over a LAN works as well as being on the same machine that is hard wired to the equipment. At least based on all my experiences and of course that only makes sense. Direct Connection
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Super Booster pricey at $95.00
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Approximately $49.00 U.S.
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USB 2.0 Cable Runs - Up to 80 Feet
Until recently finding a USB 2.0 active extension cable was not available. So those with newer and faster USB 2.0 CCD cameras they would have to spend a lot on extenders that supported the faster speeds. However, I recently took delivery of 4 USB 2.0 Tripp Lite 16 foot extenders and have been using two+ daisy chained to a distance of 32 feet or more with a newer SBIG ST-402 2.0 CCD camera and these are working just fine! The best part is they can be purchased for about $15.00 per extender! Amazon.com has these in stock at nearly 1/2 off the list price of $49.00! Need longer runs see below.
Tripp Lite USB 2.0
Active extension cables ~$25.00 U.S.
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$15.00 U.S.
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You can daisy chain up to 5 of these or 80 feet total ~24 meters!
Longer USB 2.0 Cable Runs Up to - 198 Feet Cat 5/6!
For USB 2.0 cable runs that are longer a better albeit more expensive option is the Iogear USB 2.0 extender which uses Cat 5E or Cat6 cheap network cables! I recommend these runs for over 50 feet. Having one single Cat 5/5e or 6 cable is more convenient then dealing with extenders daisy chained together and the price is similar.
USB 2 over Cat 5/6
cable model GUCE51
~$100.00 US
WARNING! You may also need an additional power supply +5 volts at 2 amps on the receiver end for longer cable runs. This is NOT included or ever mentioned in the documentation. I am still waiting on mine!
The "optional" power supply required for USB devices needing additional
power (i.e. my SBIG CCD camera) is Iogear part number 0AD8-0705-261G and
sells for $19.00 US.
What About Long Parallel Cables?
For those with a CCD camera using a parallel interface longer parallel cable runs (more than about 50 feet) are available and reasonably priced. Up to 200 feet with parallel is possible using more expensive twisted pair shielded cabling. Contact Software Bisque for pricing on custom shielded parallel cables.
Remote Console Extender
A very good solution for distances of 50 feet and up to 500 feet is not a network but rather what is called a "Remote Console Extender". The company KVM has one model PS2 KVM Console Extender, Gce250 for ~$235.00 U.S. and available through Cyberguys. This is an ideal solution and the most cost effective for best performance solution in my opinion.
The alternative is to purchase two PC's, two versions of the Windows operating system, two keyboards, two mice, two monitors, two network cards, and use a LAN configuration.
The remote console extender works without having to do anything but plug the receiver and extender devices in. One for the local machine and one for the remote. No drivers are needed, and there is no manual switching from station to station it is completely automatic!
What you have is keyboard/mouse/monitor at one station then a single controlling PC connected to all the telescope hardware and placed very near the telescope. The amount of money you save by not having to buy 500 feet of custom cabling for direct connection to all devices or a LAN easily covers the cost of the remote console device. What about using more than 1 monitor in this configuration? No problem!
If you are hurting after buying the remote console extender keep in mind you can buy a keyboard for as little as $10.00 same for a second mouse, and a 17 inch VGA monitor can be had for $100.00 or less. Even a good 17-inch flat VGA screen from ViewSonic is only $169.00! And again, in a LAN configuration you need all of this and another PC that cannot be had for anything less than about $400.00 or more for one that works well enough to be used.
The worst case scenario is to use a single monitor/keyboard/mouse and then move them to the remote location when everything is in place. However, you will love having the two monitors/keyboards/mice working simultaneously at both locations! Just use the telescope/CCD from either station the integration is completely seamless/painless and reasonably priced.
Remote Console Extender
An ideal solution to the "control at a distance" problem
This works extremely well and is the second best solution IMHO
Only a single PC is required!
Keep in mind in the above scenario you have the PC located at or very near the telescope (say under 50 feet). This means you can use very short inexpensive cables to make all connections, parallel, USB, RS232, or even wireless Bluetooth to the telescope.
What about the PC being exposed to cold temperatures? A solution is either a heating pad installed in the PC, or to place a light bulb in or near the PC (of course make sure the light does not interfere with the CCD camera and once the PC is up and running it will warm itself, turn off the light).
Keeping the PC warm enough to operate is actually quite simple and inexpensive. In a LAN you still have to deal with this too and you have two PC's to maintain.
And yes for about $750.00 there
is even an option for Web TCP/IP remote control for over the Internet remote PC
control but again that becomes bandwidth dependent and is not a "ideal"
solution but it might be the only solution if you are very patient.
Multiple Monitor support when using the Remote Console Extender
If you are like me you cannot live with only one single monitor. There is simply no substitute for having a monitor for TheSky and a second for CCDSoft (unless you have a 24 inch to 50 inch display). This way you do not have to move windows around. And you can even have another monitor dedicated to Orchestrate or Internet access/email too if you like. I have successfully used as many as 4 monitors simultaneously on a single PC. VGA cards are cheap and LCD monitors are too. Keep in mind a black and white cheaper VGA can be used for CCDSoft for imaging or with Orchestrate. These run about $100.00
Second VGA monitor extender
VGA up to 500 feet from Cyberguys!
The above is a bit pricey at $160.00 US. However, if you only need up to say 100 feet a compatible VGA extender can be purchased for under $100.00.
Awesome!
LAN Connections
Now let's say your observatory is located 50 to 500 feet from your control room or home. In this case a local area network can be a reasonable solution but, it is simply not the best solution.
LANs work well because you have one PC hardwired to the equipment and the second PC is located at some great distance. When using a GIGABIT network (now the same price as 100-based) using two gigabit Network Cards (NICS) in each PC and very inexpensive Cat6 or Cat5E cable between them you will get very reasonable performance. A 50 foot Cat6 Network cable runs about $15.00 U.S.!
LAN performance is not as good as using a single PC connected to the hardware. PERIOD! There are those that say there is no difference in performance using two PC's with Remote Desktop, PCAnywhere, or equivalent, but that of course that makes NO SENSE at all since the Network method is subject to bandwidth!
Gigabit network cards are cheap now ~$25.00 US; so there is no reason to use anything but gigabit speed in a LAN. Gigabit switches (do not use a hub but rather a smarter switch) are also on the order of only $125.00 U.S. But again, a LAN will NOT give you the same performance as a direct hardwired connection.
Even if you have ten computers connected, just use a gigabit switch and all gigabit network cards for best possible performance across the entire LAN. I use Linksys switching hardware and NetGear gigabit NICS for great performance. These all work satisfactorily, but again the performance is simply not the same as using a single PC hardwired to the equipment! Why should it be?
LAN Scenario
What could possibly be a better solution for say a 500 foot run? See the above Remote Console Extender which (IMO) is the ideal overall solution OVER even a LAN connection. And for those that run more than monitor like I do you can simply extend the second or third monitor input using and VGA extender. Very handy!
Long Serial Cables - to 1000 feet
Serial connections up to 1,000 feet 0.3048 kilometers $99.00 US. The following device will allow you to run up to 1,000 feet using standard Cat5E network cable.
Gefen serial extender
RS-232 up to 1,000 feet
uses Cat5E cable
Serial connections greater than 1,000 feet up to 1.6 kilometers (1 mile). I have only tested the above at 100 feet but works just like a charm. Look MA no DRIVERS!
In order to run longer than 1,000 feet you will need to convert RS-232 serial to RS-422/485. This can be done for about $300.00. But here for the other equipment hen you have the problem with a very long USB or Parallel camera cable run! Frankly spending $600.00 for a USB long run is too pricey for my own personal taste!
Wireless Connections
Wireless device control has its place, and can be very convenient. In fact, I have several wireless connections at my home where it was more convenient than trying to run a network cable and it is fast enough to handle the speed of the DSL connection but is a bit slow when it come to remote control, live video, and CCD image downloads.
However, there are times when I take my laptop out to the telescope and control the scope and CCD camera via the hardwired desktop computer which is inside using a wireless connection. This way I can see what is going on when I am at the telescope. Great for initial focusing (albeit slower) of the telescope where you have to use the coarse focus knob on the scope to get close to focus first. It also works great for a new installation where you are not yet polar aligned and need to be at the scope. When all is in good working order I just use the PC hardwire connected to the scope and devices locally or from a remotely using the Remote Console Extender.
I often use wireless with my Pocket PC or Laptop to browse the web. In these cases the slower bandwidth is simply not an issue because of the 6 megabit DSL connection (in my case) is the bottleneck. More commonly this is more like 1.5 to 4.0 megabits/second so the 11 mps or even 54 mps wireless connections is more than fast enough.
However, this is simply not the case when trying to use the telescope and other equipment like the CCD camera. If one were merely controlling the scope for visual observing a wireless connection is more than adequate and Bluetooth connections to the telescope is actually very convenient indeed. But having more than just the telescope in the loop, as is always the case when using a larger format CCD camera, this changes everything. Meaning wireless is not well suited for this!
Bluetooth Serial Connection to Telescopes
A wireless Bluetooth connection to the telescope is extremely
convenient. However, the distance is limited to something on the
order of only about 10 meters or 32 feet. For out in the field use
using a Laptop or Pocket PC with a wireless Bluetooth connection is
extremely convenient and a dream to use.
Although Bluetooth is convenient and it works well for RS-232 telescope control it is not an option for CCD camera control. Again there is no substitute for being hardwired in this case.
Bluetooth Connections Page
- How to connect the Paramount ME Robotic
Telescope System and other go to telescopes using wireless Bluetooth
connections!
Wireless RS232 Serial Device Wi-Fi Aaxeon
Now here is a very handy device. The unit will convert RS-232 serial communications to standard 802.11b Wi-Fi! Because the slow communications speed for telescope control is not an issue this works fine. Meaning you can use your RS-232 compatible telescope/focuser or other RS-232 serial device just as you would a normal wireless PC connection.
Aaxeon Wirless options
RS-232 using Wireless
Not tested in-house as of
yet!
Keep in mind that even if the telescope and all other serial devices (including video) are completely wireless a wireless connection to the USB CCD camera is not the ideal solution. This can be painfully slow, especially with larger mega-pixel CCD detectors!
