The benefits of a 20m active USB3 cable - Forums

Topic starter

Nov 17, 2021 · Edited: Nov 17, 2021

Tonight is frustrating … the clouds keep coming even though the forecasters said it would be broadly clear. I don't have a permanent setup, so I lugged the mount and scope out just before dusk. My intent was to quickly do a sharpcap polar alignment just after sunset and then get some imaging done. None of that looks likely and in the old days I would have been sitting in the cold waiting for the clouds to clear to do a polar alignment. BUT:

I now have an active USB 3.0 extension cable that lets me sit in the comfort of my home watching sharpac remotely and seeing if the clouds clear enough for it to solve. If it does, I will take the PC outside and make the manual adjustments. If that works, then the PC can come inside and I can do imaging in a nice warm environment.

I think I know that tonight I will be bringing all my kit back in without doing any imaging, however at least I won't have been sitting out there for hours on end getting cold.

I highly recommend these 20m or so long active cables for anyone in the same situation.

Wish me luck: there may be clear skies yet.

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Dave Ek

Nov 17, 2021

Being able to sit inside and monitor the conditions outside is definitely a plus. Another approach, if you can manage it, is to connect your imaging PC to your wifi network while it's outside, and then monitor it remotely from inside using another PC or tablet, either using MS Remote Desktop (your outside PC would need to be running the Pro version of Windows) or something like TightVNC. The AsiAir Pro uses an approach something like this (although I believe it's Linux). In my case, I purchased an inexpensive HP laptop to leave on a table outside near my gear, and then connect to it using Remote Desktop from inside. Once my gear is set up and polar aligned, I can do pretty-much everything else from inside. I also ended up purchasing a wifi extender for my network in order to provide better coverage to my outside gear. (FWIW, I also do not have a permanent setup outside.)

No matter how you do it, being able to control your imaging gear from inside is a game-changer, especially in winter.

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Andy Wray

Topic starter

Nov 17, 2021

Dave Ek:
Being able to sit inside and monitor the conditions outside is definitely a plus. Another approach, if you can manage it, is to connect your imaging PC to your wifi network while it's outside, and then monitor it remotely from inside using another PC or tablet, either using MS Remote Desktop (your outside PC would need to be running the Pro version of Windows) or something like TightVNC. The AsiAir Pro uses an approach something like this (although I believe it's Linux). In my case, I purchased an inexpensive HP laptop to leave on a table outside near my gear, and then connect to it using Remote Desktop from inside. Once my gear is set up and polar aligned, I can do pretty-much everything else from inside. I also ended up purchasing a wifi extender for my network in order to provide better coverage to my outside gear. (FWIW, I also do not have a permanent setup outside.)

No matter how you do it, being able to control your imaging gear from inside is a game-changer, especially in winter.

I do agree .. the wifi route is probably easier for most. Unfortunately we decided on special invisible metallic coating on our double-glazing when we replaced it that acts like a perfect faraday cage!?! Kills all mobile signals coming in from outside and kills all wifi signals going the other way; I won't be doing that again in a hurry. As you say though: whichever way you do it, it is a game-changer. We just need to make sure the cabling is right on the scope so that there is no chance of cable snags when we are so far away physically.

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Lynn K

Nov 17, 2021

I have use 30ft activated USB2 to motitor a session from a tent. It worked well. When I put in a POD observatory, I still used the 30ft activated USB2 cable to run in the house. Since the obsevatory was permanent, the cable was run underground into the house. I havev a
a littlev wall desk mounted in the kitchen that I run the system from. You could run a permanent USB cable into your house from a permanent pier. The mount could be permanetly mounted and polar aligned.

A better solution, which I now have gone to, is a USB to CAD5-6 cable adapters/converters. Once I started taking a travel trailer to my dark site, I needed more that 30ft of cable. I now run about 40ft of CAD5 cable into the trailer. The USB to CSD5 converters can go up to 300ft. I am now doing the same thing from the POD to the house.

Lynn

Andy Wray

Topic starter

Nov 17, 2021 · Edited: Nov 17, 2021

Lynn K:
I have use 30ft activated USB2 to motitor a session from a tent. It worked well. When I put in a POD observatory, I still used the 30ft activated USB2 cable to run in the house. Since the obsevatory was permanent, the cable was run underground into the house. I havev a
a littlev wall desk mounted in the kitchen that I run the system from. You could run a permanent USB cable into your house from a permanent pier. The mount could be permanetly mounted and polar aligned.

A better solution, which I now have gone to, is a USB to CAD5-6 cable adapters/converters. Once I started taking a travel trailer to my dark site, I needed more that 30ft of cable. I now run about 40ft of CAD5 cable into the trailer. The USB to CSD5 converters can go up to 300ft. I am now doing the same thing from the POD to the house.

Lynn

Lynn,

Thanks for that. What products are you using? I'm planning to move house and set up a permanent observatory and was thinking about how to go over the 20m limit I have with active USB.

FWIW: I don't plan to have a PC at the scope end of things, so the USB needs to be extended out so that it connects directly to the cameras, mount, guiding scope, filter wheels etc. at the far end. Currently my setup is: PC in my study, long active cable to a powered USB hub on the tripod leg, USB fed to all devices from there.

BR

Andy

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Lynn K

Nov 18, 2021

Hi Andy, This is the unit that I use and prefer. Cheaper and works as well as the more expensive ICRON. I have three of the StarTech and a 500ft range ICON that I bought used.

https://www.amazon.com/StarTech-com-Port-2-0-Over-Cat5-Extender-Cost-effective/dp/B00T9RTT2U/ref=sr_1_5?keywords=4+port+usb+to+cat5+extender&qid=1637198852&s=electronics&sr=1-5

This is the popular brand ICRON with a good reputation. Both StarTech and ICRON can be bought for a 500ft range. Not needed unless you have a observatory far from the house.

https://www.amazon.com/USB-2-0-Ranger-2304-NA/dp/B00U6K4PC8/ref=sr_1_18?keywords=ICRON+4+port+usb+to+cat5+extender&qid=1637198478&s=electronics&sr=1-18

One unit has the USB ports that your equipment at the mount will plug into. The other is at the other end of the CAD5 cable and converts back to USB to the laptop.
I have found these to be more dependable than a USB Hub port. I run the mount (Mach1) from serial through a Serial-to-USB hub, Trius Starlight Xpress cameras with filter wheel & guide camera going through the camera USB hub (only one usb coming from all three), Starlight/Optec focuser and sometimes a Optec rotator. That is my Four USB inputs. I have never seen one of these units with more that 4 ports. There may be a band width limit. The only issue I have had is sometimes the filter wheel will not load in Windows. I also had the problem with a activated USB cable. I think that problem is caused by the camera hub. It is solved by going outside and unpluging and re-pluging in the filter wheel.

Lynn K.

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Christian Großmann

Nov 18, 2021

Andy Wray:
Lynn K:
I have use 30ft activated USB2 to motitor a session from a tent. It worked well. When I put in a POD observatory, I still used the 30ft activated USB2 cable to run in the house. Since the obsevatory was permanent, the cable was run underground into the house. I havev a
a littlev wall desk mounted in the kitchen that I run the system from. You could run a permanent USB cable into your house from a permanent pier. The mount could be permanetly mounted and polar aligned.

A better solution, which I now have gone to, is a USB to CAD5-6 cable adapters/converters. Once I started taking a travel trailer to my dark site, I needed more that 30ft of cable. I now run about 40ft of CAD5 cable into the trailer. The USB to CSD5 converters can go up to 300ft. I am now doing the same thing from the POD to the house.

Lynn

Lynn,

Thanks for that. What products are you using? I'm planning to move house and set up a permanent observatory and was thinking about how to go over the 20m limit I have with active USB.

FWIW: I don't plan to have a PC at the scope end of things, so the USB needs to be extended out so that it connects directly to the cameras, mount, guiding scope, filter wheels etc. at the far end. Currently my setup is: PC in my study, long active cable to a powered USB hub on the tripod leg, USB fed to all devices from there.

BR

Andy

Hello Andy,

personally I had little experience with active USB cables. But I use one (5m only) to connect my scope to the imaging PC, that is remotely controlled over an Ethernet network. I do have problems with the active cable. I am only able to use it with USB 2.0, although it should support USB 3.0. There may be an issue with the cable impedance. All the PCs I tried, did not work correctly with this cable as a USB 3.0 connection. Either only some connected devices could be used or the connected hub itself is not recognized.

Maybe, I have a bad example, but I just want to mention this. The USB bus is not made for long cables. The bus speed and the occuring errors that slow down the communication (corrected by the transmission protocol and therefore not directly visible for the user) depends on several physical stuff that is effected much by the cable length. I think, the Ethernet solution should be preferred, because it is made for such applications.

This, of course, is not a must, but something to keep in mind.

CS

Christian

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Henrique Silva

Nov 20, 2021

I use a 10 meter active 5V USB 3.0 cable.

Working at home is another comfort and on cold nights, even better!

It works without problems. I just recommend a good cable because I've had one from another brand that doesn't work well, maybe a sync problem between cameras and pc.

Regards,

John Hayes

Frequent contributor

Nov 20, 2021

Andy Wray:
I'm planning to move house and set up a permanent observatory and was thinking about how to go over the 20m limit I have with active USB.

FWIW: I don't plan to have a PC at the scope end of things, so the USB needs to be extended out so that it connects directly to the cameras, mount, guiding scope, filter wheels etc. at the far end. Currently my setup is: PC in my study, long active cable to a powered USB hub on the tripod leg, USB fed to all devices from there.

Andy,
If you are going to go to the expense to set up a permanent observatory, you are thinking about this in the wrong way. You are much better off setting up the observatory with a local PC and either an internet connection (preferred) or a buried network cable. Then you can run the telescope remotely from inside your house using something like Chrome Remote Desktop over the internet or by plugging your “every-day” PC into the network cable. Network cables can easily run 100m without a problem; although using either WiFi or the internet to connect wirelessly is a better way to go. Among the many advantages of having a local PC running your system, is that if anything goes wrong with your connection, the telescope PC will still keep chugging along without missing a beat. And the cost of a dedicated telescope PC is minor relative to the cost of your scope and the observatory. This is how I run my telescope in it’s own observatory—nearly 8,000 miles away in Chile! I sign on through the internet using Chrome Remote Desktop and run the scope as if I were sitting right next to it. Getting all this stuff running is surprisingly easy once you start working on it. You have to look at that local telescope PC as a piece of equipment that is as essential to running your telescope as your camera—or mount. USB connections are often the flakiest part of any telescope setup and trying to run a scope over a long USB cable is a recipe for disaster in the long run—particularly if you build an observatory.

John

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Andy Wray

Topic starter

Nov 20, 2021 · Edited: Nov 20, 2021

@John Hayes I can see the benefit of having a PC at the telescope end and a network connection via the internet or via local network. In addition to the increased reliability versus trying to run long USB cables, I can see that that would allow me to do much more such as remotely power cycling/rebooting individual items etc.. As you say, it also allows the captures to continue even if the connection has a problem.

Right now, I'm having to deploy the scope on a patio in my garden just on the nights I want to image, so the extended USB is working well for that. i.e. I have to run a power extension cable across the lawn, so running the USB at the same time adds no real effort. I will take your advice though and deploy buried power and network cables to the observatory when I move. Ref WiFi: If I'm having to dig up the garden to run power cables, I may as well run network cables at the same time.

Alan Brunelle

Nov 21, 2021 · Edited: Nov 21, 2021

Andy Wray:
Right now, I'm having to deploy the scope on a patio in my garden just on the nights I want to image, so the extended USB is working well for that. i.e. I have to run a power extension cable across the lawn, so running the USB at the same time adds no real effort. I will take your advice though and deploy buried power and network cables to the observatory when I move. Ref WiFi: If I'm having to dig up the garden to run power cables, I may as well run network cables at the same time.

I'm with John on this. I am also on a patio with a single extension power cable and used to do as you did with a laptop out on the patio. My patio is however about 90 ft to the house. I also had to use a powered usb hub to reliably get all the gear to work without hiccups on the image downloads. Even still, I found myself going into the house on most jobs and leaving the laptop out on the patio to do the job. Doing away with the hub and laptop worked wonders regarding reliability and my not freezing! The reliability with a rig-dedicated computer comes about partly because all the data connections are local with very short cables. But also partly because I can check on performance, m-flips, crashes, focus, etc. from the comfort of my bedroom or office. I understand the issues around your Faraday cage house, so an ethernet cable would do the job just fine. But it is also easy to mount an outdoor repeater on the outside of the house if wifi is preferred.

There are many small computer options for operating a remote rig like what you are doing. Some dedicated and many many small computers (nucs) from multiple vendors. For simple operations, the data demands, even for large image file-sized cameras require rather modest computing power and lower costs. I would say, try to get something that has sufficient usb 2 and 3 ports to stave off the use of a hub for as long as possible. And of course it should have on board wifi and one or two ethernet ports. And on board, M2 form ssd capabilities for the storage of lots of data that you will hopefully be collecting!

Because I am not doing remote imaging, I gather my data in the AM via a usb stick. I would like to learn about other methods of remote computer operation, such as how you access the subs on the remote computer from a remote observatory. But this ends up being a bit off-topic for your purposes.

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