Long USB and high data connection issues

[rogerg]

Hi all,

I'm having intermittent issues with data connection between DSLR cameras and computers where my USB cable lengths are at their limit of 5m. I'm looking for any comments on suggested solutions before I go to the extreme of major re-working of my USB "network".

I have two cameras in question - 350D and 7D. The 7D is significantly more problematic over the same cables than the 350D, presumably due to the significantly greater data transfer requirements.

I have this chain of USB:

DSLR
1.2m USB cable
USB Powered Hub
5m USB cable
USB Powered Hub
3m USB cable
PC

Any suggestions on how I can improve the reliability?

Options I see in front of me include:

- a small PC at the base of pier which means 2.2m USB to camera only, and then use remote desktop or such to access DSLR functionality from there. This is a costly, perhaps cost prohibitive, solution, and also leaves a PC box at the base of the pier (undesirable). I have wondered what minimal sized PC box I could find for this.

- direct 3m cable + 1m cable (total 4m) from DSLR to PC. This is OK in some situations depending on telescope position for in-person-usage but isn't suitable for my normal automated observing because it restricts telescope movement and has cable strung across the gap from PC to scope (normally cable duct through floor).

- using a Canon Wifi grip instead of USB. This is cost prohibitive from what I've seen - about $1400!!!

Thanks,
Roger.

[DavidTrap]

Have a look at this thread (http://www.iceinspace.com.au/forum/showthread.php?t=75934&highlight=Lindy+usb).

Happy to report this system is working well for me. No issues guiding, focusing, controlling mount or downloading from CCD camera.

DT

[Visionoz]

Roger

Perhaps you've also heard of the Aten USB2.0 Active Extension 5M cable? It is cost-effective as well

HTH
Cheers
Bill

[rogerg]

Thanks guy's. This and PM's I've received have reminded me about USB extension over Ethernet. I think that's the path I'll take, using the ATEN USB Extender. Seems like $75 for that will solve my problems.

Roger.

[mswhin63]

There is a 10m and 20m version - http://www.jaycar.com.au/productView.asp?ID=XC4120&form=CAT2&SUBCATID=1044#6

[mswhin63]

USB over Ethernet doesn't suit all products as in most cases, the box has standard driver converters. Canon cameras are propriety converters and are not represented. This is the reason why Canon can charge $600.00 on a wireless device to extend the camera functionality.

If someone has found something would be nice for all the know.

[rogerg]

I always forget about JayCar at just the wrong time :) Thanks Malcolm.

[midnight]

Try USB via ethernet.

Here at work, part of our control system runs 200m via fibre. Ie the computer is 200m away from the desk. The connection is done via fibre optic ethernet and a simply USB converter at each end. Happily runs USB2.0 with a Canon 40D + keyboard + mouse + WD 750GB local drive + several memory sticks with no reliability issues. Been operating since 2009 when it was first commissioned.

You probably don't need this level of hardware but USB over ethernet is a viable alternative and commonly used in heavy industry to overcome limits of length and keep computers in proper air conditioned areas and secured (eg power generation).

Cheers,
Darrin...

[troypiggo]

Probably a dumb question, but can you use those USB/ethernet converters over wireless connections? I mean plug each ethernet end into a wireless router.

[midnight]

Interesting question? I have not done that type of setup but if the ethernet converter is acting like a point to point host, then possibly yes as the device will appear on the network with an IP address. I don't know for certain but one could theoretically go USB->Ethernet->Wireless router-> Remote computer with wireless connection. All without running a long cable.

I should try that as we effectively use a ethernet to fibre media converter to send the data over the fibre network to the other end.

Maybe someone with some more wireless/routing experience could shed some light on this.

Cheers,
Darrin...

[mswhin63]

I think these are USB over ethernet cable not so much as over ethernet itself. Ethernet cable twisting and balun (Balanced/unbalanced transformers) construction allows data to be transfer along the cable better than standard cable for USB.

These sort of system have been around for years as an alternative to long cable before bluetooth took hold with class 1 bluetooth. Even Class 1 can't run anymore than 100m at best.

[alistairsam]

Hi,
i havent used them but the simple usb over ethernet adaptors may not be true ethernet although it uses UTP cables. I don't think they use Baluns or ferrite beads, but they may work by virtue of the twists in a UTP cable that effectively cancels EMI and crosstalk and allows propagation over distances.

but if the usb over IP devices use Layer2 Ethernet frames to encapsulate USB I/O, or Layer 3 IP addresses, then no reason why it cant be bridged with a wireless AP.
i'll be trying this out pretty soon.




Darrin, you mention you're using a canon 40D wtih a fibre optic cable. so is the 40D being detected as a USB device on the PC/laptop with fibre inbetween? what USB converters are you using at each end and are you using media converters for copper to fibre conversion?

i've tested serial over IP devices wirelessly and it works fine.
i use a software that maps a COM port to an IP address. you then just choose the appropriate COM port and you have serial over wireless connectivity.
i just need the USB bit to work as well.

[rogerg]

Received my ATEN USB extender just now (over CAT5). I see now it's USB 1.1 not USB 2. Doh!

Will try it over the weekend and see how it goes.

[DavidTrap]

All of the ones I saw that worked like that were all USB1. This is why I went for the Lindy system.

Not sure if this is true or not, but apparently there were some patent issues which explained why USB2 via ethernet cable was really expensive. Do your research and anything that extends USB2 over ethernet cable is really expensive ($>500)!!!

DT

[mswhin63]

USB over Ethernet only works on generic drivers so Canon and Nikon Cameras won't work as these are specific propitiatory driver and cannot be converted to Ethernet.

I am looking at USB extender but even they are unpredictable. I have a USB hub via Ethernet now but only allows simple device like printers and external hard drives.

So far as been use by all people and working are:
USB 5m un-powered cable
USB 20m Powered cables
Skyfy (propitiatory drivers)

Even Class 1 and 2 Bluetooth cannot work with Canon as they only allow generic driver throughput like Comms and audio and Video and images.

Canon uses a single USB for both images and signalling (ISO selection, Aperture and other functions) and is why specific drivers are required.

[rogerg]

The ATEN USB Extender (using CAT5) works fine, no problem using remote live view, control, or download.

Both live view and download using the 7D are slower because of the 12mb/s speed rather than USB2. I will be using this with the 350D which is smaller downloads, but certainly a disadvantage is the speed. Perhaps that makes the Lindy system worth it. I remain skeptical about the "active USB" cable type aproach, as I would have thought if that would work, then two powered hubs 5m apart would work (which isn't reliable for me).

Roger.

[mswhin63]

Hi Roger, USB hubs stacked together add to the latency of the complete system. USB requires certain timing to be recognised and when adding multiple components to add to that time until it become un-reliable. The powered cables are designed to transmit at the speed required, the powering are active transmission equipment to boost the signal levels and maintain that speed over longer leads.

I am going to experiment with Bluetooth module to see if they can be modified to work USB 2.0 directly instead of just comms.
Most work using comms conversion which is not able to send Video or images.

[midnight]

Yes, the 40D is recognised.

Basically it is media converter with 4 USB ports that has an RJ45 connection but is actually ethernet and not using the twisted pairs inside like a balanced extender. Then we have a Moxa RJ45 to fibre via LC connectors from memory. The LC fibre connectors patch to our 16 way fobot and then multimode 62.5/100 fibre down to the other building and then the setup is reversed.

What I do not know is if software was installed to drive the USB to ethernet hub. We do get reliability out of this and I can find out more.

Cheers,
Darrin...

[alistairsam]

thanks. would you have a pic of this usb to ethernet coverter or model/make.
as you says its ethernet, i expect this will bring up a link light on a network hub or switch. that denotes link and protocol are up which means it can be switched / routed. you won't need drivers for this.
this also means it can be ported to a wireless AP.
hope to get my hands on one of these soon.

[rogerg]

I saw in Jaycar today that they have USB to Ethernet (not just CAT5 but Ethernet) adaptors and they're 10/100/1000 full duplex but don't quote a transfer speed. They also have USB over CAT5 for a cheap price (think it was $39). Their range of USB Active Extension cables is good too (as Malcolm mentioned).

[mswhin63]

I have also seen these products as well. I still have my reservation on remote control of Canon or any other DSLR but I wait abated breath. I consulted a couple of specialist computer stores and they have not been able to say that DSLR or any other device can be controlled this way either.
I have no doubt that the long cable will work.

I hope with the weather being quite poor here that I am going to modify my Bluetooth EQASCOM connection to remote control DSLR, but that will be another test.

[rogerg]

Isn't Bluetooth too low a bandwidth for it to be worth using ?

[mswhin63]

Possibly but Canon already make a wireless interface for the DSLR camera but at $600.00 each is a bit much. Fortunately it won't cost me much to find out.

[rogerg]

In theory you should max out at about 3Mbps as compared to the canon one which runs on ABG wifi at 54Mbps ... but like you say, will be interesting to see what you get.

Roger.

[BlueAstra]

I’ve been following the conversation on long distance comms with some interest. I’ve had some success with USB repeater cables, but it was a bit hit and miss, depending mainly on the manufacturer of the cable. You could never be sure it would work until you tried it. In my case by far the best solution was a local PC, operated by remote desktop over network cable. It’s not without some issues of its own, but avoids many of the common USB issues.

The equipment setup is a ZBOX HD-1D11 (Atom D510 @ 1.66GHz, 2GB ram, 64GB SSD, XP operating system, 6 USB2 sockets) Nettop running:

Direct USB to Hitec EQDIR module/EQ6
Direct USB to Lodestar guide camera
Direct USB to SX-H16 CCD camera.
Direct USB to Canon 1000D (if fitted) or DMK camera (if fitted)
Direct USB to Powered 7 port Hub running:, SX Filter wheel, Gamepad, Shoestring FCUSB
Direct USB to Memory Stick

Software:
Maxim DL v5.14 running SX-H16 camera, SX filter wheel, EQ6 mount via EQMOD/POTH hub (sometimes EQ6 direct), Gamepad
PHD running Lodestar guide camera
FocusPal running FCUSB focusser
Windows remote desktop software
Canon camera control software
IC Capture (DMK)
Starry Night

The USB cables are generally 1-2m long. I current run the remote PC over a 10m network cable from a local (house) PC. Everything works well, and images are stored to the memory stick at the end of a session. I set up and tear down each session, and the PC stays with the scope in the shed. I’ve not had any issues with cold, moisture, etc, probably because of the heat generated within the Nettop. My only issue has been with trying to operate Starry Night, Windows remote desktop doesn’t like OpenGL. TeamViewer works though.

So from my personal point of view I can recommend the remote PC solution to long cable operation.

[mswhin63]

Hi Graham,

Good observatory set-up. Local network is good for Remote desktop application although I am considering field operations. Minimal cabling to a single computer. I don't have an observatory as I rent so the only dark skies I can get when not raining is away from the burbs.

I am though considering redesigning my van to take a PC installed with wiring to the mount in a single cable loom and run a wireless keyboard and mouse and gamepad controller for EQMOD. I have just removed one of my 12V PC from duty going to clean it up and install in the car.

[alistairsam]

Hi graham

the remote PC is a workable solution but i think if we get the canon and other usb working over 802.11a/b/g/n wireless would be ideal.
I'll be testing it soon.
much higher bandwidth than bluetooth.

I use lantronix terminal servers for serial to ethernet over wireless and it works fine. as it has 16 ports, a number of serial devices can be interfaced.

I like teamviewer as well but for light connections, i find ultra vnc much quicker.

[alistairsam]

Malcolm,
the wireless kb/mouse is a good option as well, why not look at wireless kvm's? that way you'd need just one pc.

[mswhin63]

I have to agree that USB over Ethernet would be a far superior option for bandwidth although size and expense is a bit of a problem. I have a couple of Bluetooth modules that spec'd up to 3Mb/s throughput on USB 2.0 so I am hoping this will be enough for typical Astro applications. Just having problem getting it interfaced at the moment. Nothing available off the shelf either. Maybe it is not very popular for the majority of people.
Time is another issue as I have just commenced Uni studies (full on) although had enough time to make a small light-box tonight :thumbsup:

[spine]

I use the Lindy USB extenders (at home and in a work enviroment) At home My runs are around 20 meters, and both work fine.

[mswhin63]

All nice options although for 20m for single or 4 port USB port the powered cable with a hub is far cheaper. There is no requirement to protocol change USB because the speed restriction are based on the end points. Will go no faster than the equipment that outputs at USB data rates.