USB 3 cables for Dedicated Camera back to Remote Computer

[teoria_del_big_bang]

I think this is a well talked about subject but I would like to hear what other people do about getting data back from their dedicated cameras to remote computers.

I have a ZWO ASI 1600 MM-Pro which has USB3 as opposed to USB2 I used on my DSLR. Also there is a USB2 hub on their so I have my filter wheel and guide camera connected to these which means apart from the USB2 from the mount and Polemaster (which only is required at setup so can be omitted really) I only have one USB3 cable to go back to my computer some 10 M away, AND the USB2 from the mount.

When I had my DSLR I had all sorts of issues with USB cables and signal loss, slow frame rates from guide camera and so on and in the end bought a USB via Ethernet unit but even then had issues and ended up sending data from camera back on its own USB2 cable (Extended to 10 M) and the mount, guide camera, Polemaster through the USB over ethernet.

This worked fine for camera data but guide camera was very temperamental and slow frame rates and sometimes dropped out altogether.

So thinking some of the issues may have been my old desktop computer I now I have bought a new much faster one. I also have a decent spec laptop.

But what is best thing to do.

a) Use the USB over ethernet (which effectively at best is only USB2) for both mount and the USB3 from camera (including signals from guide camera and filter wheel) .

b) Get an extension USB 3 cable for camera and use either an extension cable or usb over ethernet for mount (I don't think this is critical so either should work).

c) Connect camera USB3 to Laptop USB3 port with provided short cable and remote desktop or Teamviewer from remote computer (ideally would not want to leave laptop outside all night if I can avoid this method)

Thanks for anyone who has been patient enough to listen to my ramblings an apologize that my understanding of USB is not great but any thoughts of how best to do this or just to say how they do it will be gratefully received.

Steve

[Dr_Ju_ju]

Personally, I'd forget any USB lead over 3\5 metres, and definitely no repeaters\converters (they are not worth the money, unless you want to drive a printer), and I have tried everything.

I use local (to mount) computers, whether that be Windows or Linux based, that have appropriate USB ports, i.e. USB 2 and USB 3 ports, and wired ethernet ports (preferably gigabyte).

If then needed, I use good quality, powered, USB hubs at the mount, to provide any additional ports, as needed. 

This means, that, at the mount (in a weatherproof enclosure), I have the computer & power supplies etc.

I then have three cables back to the house, an armoured, separately fused mains cable and exterior grade ethernet cables, one spare.

I have all the acquisition and control software on the local computers, but save all images to networked disk stores, inside the house. This is all controlled from my main PC using remote desktop (for both windows & Linux (using XRDP)).

Since moving to this setup, I've never had any issues with connectivity & control.....

 

[Anthonyexmouth]

i use a 10m lindy usb3 lead plugged into a hub with my asi290/mount/dlsr/asi120 guide all working fine. no issues at all. just make sure you get a good usb 3 cable, not a cheap ebay one. 

[JamesF]

If you're going to try it then I think you must use high quality cables.

However, be aware that USB3 is only intended to work over distances of up to three metres.  Beyond that you're outside the spec. for the protocol.  That doesn't mean it won't work, certainly, but it may mean it won't work reliably, where the conditions under which it will work are not in the least obvious.  You might even find that two apparently identical set-ups behave differently, or even that some nights it will work and others it won't.

I appreciate that it's really convenient to just have the one cable, so I'd not suggest it isn't worth trying, but have a plan B

When i get around to the wiring in my observatory however, I shall follow the same path as Julian.

James

[Skipper Billy]

I wouldnt use a USB cable (USB 2 or 3) any longer than 5 meters - it's just asking for trouble.

I have tried a few solutions - the two most successful were converting the USB to Cat5/6 - this worked reliably at 50m - a top quality powered USB hub in the obsy and CAT6 cale to the PC in the house. I used on of these - https://www.uk.insight.com/en-gb/productinfo/network-accessories-and-misc-networking/0004374189-00000001?gclid=Cj0KCQiAn4PkBRCDARIsAGHmH3e0T5vtankggDcCzURT_iTmkiMY6ZXkPHYvjbFT5H8e3u1mXgiTSB0aAkIKEALw_wcB

The socond solution was born out of my desire to have a PC in the obsy so I could be 'out there' and still have access to the computer to adjust things.

I now have a very similar setup to Dr_Ju_Ju - a PC in the obsy - a pc in the house - linked by CAT6 cable (or wifi - I can choose) - using RDP - absolutely flawless performance and with a screen in the obsy I can control it or alter stuff from either location.

 

[Anthonyexmouth]

this is the one i use

https://www.lindy.co.uk/cables-adapters-c1/usb-c449/10m-usb-3-0-active-extension-cable-p6917

not cheap but not too pricey either, i was using a 15m version until a sliced through it when i dropped a counterweight on it. was using the 15m for a year with no probs. 

[cjdawson]

The setup that I've gone for is to plug in a StarTech USB 3.0 hub directly into the laptop, using a short cable.

Next from hub to my ZWO Asi1600-MM Pro I use a 5 meter lindy usb 3 cable

Then I use the short usb cable plugged into the ZWO Usb Port to connect to the filter wheel.

My Starlight Xpress Superstar is connected to the hub via a seperate USB 2 cable from lindy

 

It does mean that there's 2 USB cables from laptop to scope.   This allows me to detach the ASI1600 when I'm doing a polar alignment.  As there is a clearance issue when I try to point the scope up to the pole.  the camera won't fit between the fork mounts.    So I can do the polar alignment using the Starlight Xpress using SharpCap.  Then it's simply a case of adding the extra camera once I've done the 2 star alignment that my scope needs.

[teoria_del_big_bang]

2 hours ago, Skipper Billy said:

the two most successful were converting the USB to Cat5/6 - this worked reliably at 50m - a top quality powered USB hub in the obsy and CAT6 cale to the PC in the house. I used on of these - https://www.uk.insight.com/en-gb/productinfo/network-accessories-and-misc-networking/0004374189-00000001?gclid=Cj0KCQiAn4PkBRCDARIsAGHmH3e0T5vtankggDcCzURT_iTmkiMY6ZXkPHYvjbFT5H8e3u1mXgiTSB0aAkIKEALw_wcB

That is exactly the same one as I use and to be honest not with too much success. My new computer arrived today (tower) so I will see how that goes and maybe try a different CAT5/6 cable. I will persevere with this as the hub is not cheap and I bought it after it was recommended by a few people on this forum so I know it can work.

I suspect that the fact the camera is USB3 and the hub is USB2 will not have a great effect or cause any speed issues?

Steve 

[Anthonyexmouth]

33 minutes ago, teoria_del_big_bang said:

That is exactly the same one as I use and to be honest not with too much success. My new computer arrived today (tower) so I will see how that goes and maybe try a different CAT5/6 cable. I will persevere with this as the hub is not cheap and I bought it after it was recommended by a few people on this forum so I know it can work.

I suspect that the fact the camera is USB3 and the hub is USB2 will not have a great effect or cause any speed issues?

Steve 

Using a usb2 hub will only be an issue if you need the usb3 speed for video imaging of planets. The high frame rate is beneficial there, for long exposure it's not going to be a problem. 

[Dr_Ju_ju]

I'm sorry to say, USB 2.0 hubs are no good when there are USB 3.0 devices in the mix, as they are incapable of the higher data transfer speeds, especially when it comes to image downloads, and other USB 2.0 devices that get 'upset'.

For me this is the USB to serial adaptors, used to drive\guide the mount, & yes they are FTDI based ones; hence dedicated USB2 & USB3 hubs.

[teoria_del_big_bang]

13 hours ago, Dr_Ju_ju said:

I'm sorry to say, USB 2.0 hubs are no good when there are USB 3.0 devices in the mix, as they are incapable of the higher data transfer speeds, especially when it comes to image downloads, and other USB 2.0 devices that get 'upset'.

For me this is the USB to serial adaptors, used to drive\guide the mount, & yes they are FTDI based ones; hence dedicated USB2 & USB3 hubs.

What does this mean regarding the USB2 hub on the ZWO camera then ?  Does it mean I will get far better transfer of pictures via the USB3 to computer if I do not use it?

Steve

[Dr_Ju_ju]

That works as they are short cable runs, and most of the time do nothing, apart from move the filter wheel & get the data (images) off the main and guide cameras. But none of these operations happen at the same time, e.g. moving filter wheel happens very rarely, main imaging download occurs every 2~5 minutes, but during this process, guiding is halted, so no data from the guide camera, then vice versa.

The one thing that does require high throughput, is the mount control, and as that is USB2 based, I run a separate USB 2 lead from the computer, to ensure there are no data bus conflicts.

[Anthonyexmouth]

mount control doesn't require high data speeds at all, its working at a fraction of the capacity of the original USB 1 standard, the data transfer is tiny and slow, you could run it over a wet piece of string. USB 2 is more than capable of running everything except the most demanding frame rates needed for high bandwidth video capture. 

For really long runs (40+ meters) it is cheaper to use cat5/6 but then its only running at usb2 speeds anyway. A high quality active usb3 cable up to 20 meters should give no problems at all, cheap eBay ones are probably going to be dodgy and hence fuel the argument that long usb cables are no good. 

[pete_l]

There are many "issues" regarding USB: cables, connectors, hubs and software drivers. Ans like a chain, the whole mess is only as good as the weakest link.

If you are powering devices from their USB cable I would strongly advise watching this: Youtube video from Andreas Spiess In particular, pay attention to the voltage drops that can occur. Even when operating within the USB spec, you can get much less than 5 Volts going to your device.
Personally, I would give each data intensive (i.e. video) USB link its own cable back to the PC, unless you are very confident in the abilities of any hub you might use.

My preferred solution is the same as dr_ju_ju - have a computer at the mount. I have a small NUC / Brix PC on the mount and can feed USB3 directly in to that. My low speed devices (focus, mount, power) all get fanned-out from a small hub and the USB 2 guider cam also goes straight into the PC.

[teoria_del_big_bang]

23 hours ago, Anthonyexmouth said:

this is the one i use

https://www.lindy.co.uk/cables-adapters-c1/usb-c449/10m-usb-3-0-active-extension-cable-p6917

not cheap but not too pricey either, i was using a 15m version until a sliced through it when i dropped a counterweight on it. was using the 15m for a year with no probs. 

 

Do you connect a 5V power source to it as well ?

[Anthonyexmouth]

7 minutes ago, teoria_del_big_bang said:

 

Do you connect a 5V power source to it as well ?

No, my hub is powered so doesn't need it. If I only had one high powered device connected to it I would. 

[Juicy6]

4 hours ago, Dr_Ju_ju said:

 

The one thing that does require high throughput, is the mount control, and as that is USB2 based, I run a separate USB 2 lead from the computer, to ensure there are no data bus conflicts.

With my last HEQ5 Pro mount and EQMOD I could measure an absolute max throughput of 14 kB/s. But mostly it stayed around 4-5 kB/s.

[noah4x4]

I have an Atik Horizon, which has the same large, high resolution sensor as the ASI600. Frankly, USB or HDMI cables are useless beyond a few yards. It took me an expensive year of discovery, but here is a perfect wireless solution with an unexpected twist.... it will even handle 4k screen data!

Affix a small mini-computer at the scope. I use an Intel NUC with Iris 640 Plus Graphics to benefit from its (exceeding) 4K UHD output. I suggest at least an M3 or i3 processor with plenty of memory/storage. Your individual subs can exceed 48Mb.

Install Windows 10 Pro; camera software; scope and focusser control software etc on that computer. This computer will be the 'workhorse' and run 'headless'

You control that from a second computer indoors using Windows Remote Desktop . You connect the two computers by EITHER 802.11n/ac wireless or cat 6 cable. The computer indoors doesn't need to have Window 10 Pro. But it will need a 4k graphics card if you want to output to a 4K monitor. If limited to 1080p HD that too is very good, but I wanted to utilise the full resolution of my camera.

This route works fine with lesser cameras or if run with a 1080p HD display. But in my experience,  large sensor high resolution cameras like the Horizon or ASI600 will tend to stutter slightly and suffer from a little annoying lag. Here is the kicker...... and you won't find this is any "Consumer Guide to Windows".....

Disable RemoteFX compression via Windows 10 Pro Group Policies. 

Whether using wireless or cat6 cable disabling this largely undocumented feature resolves a myriad of challenges and will turbo charge your WAN/LAN network permitting uncompressed 4k screen data to flow freely. This compression artificially throttles Windows Remote Desktop to under 10 Mbps even if you have a 433Mbps + wireless or cable network. But don't do this on your business network or over the Internet as it is designed to prevent any single user choking a commercial network with too much data, but on your home astro WAN/LAN release its power!  

This "Windows IT Professionals" paper from Microsoft explains;

 https://docs.microsoft.com/en-us/windows-server/administration/performance-tuning/role/remote-desktop/session-hosts

The relevant section starts...

RemoteFX data compression

Microsoft RemoteFX compression can be configured by using Group Policy under Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Remote Session Environment > Configure compression for RemoteFX data (read on from there....)

But I recommend reading the full paper.

There are, of course, other options to Windows Remote Desktop  like TeamViewer, but all suffer from extreme screen data compression that constrains screen data flow and hence don't work so well with screen data intensive 16 megapixel cameras. I guess they too have 'hidden' tools to reduce the levels of compression, but I never found them. The extra control you enjoy in Win 10 Professional is well worth the upgrade price. Enjoy!