Cables, bandwidth and power (or lack thereof!)

[Twisted Lip]

Hi all

This is a pretty general question about cables and the like and I've posted it here in the imaging section as I think we're the people who end up with these problems!

Sadly I haven't been out much over the summer and only starting again for the winter sessions (just as the weather turns rubbish you say? lol) but I've added a few things to the set up which I'm now only starting to use in anger and have caused a few issues.

Anyway to cut the back story short I have a laptop (2 USB ports, 1xUSB2.0, 1xUSB3.0, Windows 8, etc) that runs the setup. The mount is an NEQ6, DSLR and Lodestar is still being used to guide. Traditionally I only ran the imaging aspects from the laptop and used the Synscan handset and ST4 port to run the mount and guide. At SGL 9 this year Gav (and a few others) rightly convinced me to use the lappy for everything. As such I bought a HITEC Astro EQDIR cable which - after taking a long while to get working - is great and alongside Cartes du Ciel, APT, etc works an absolute treat.

So here is the problem.

I've only recently managed to get back outside and on the occasions I've used the setup, CdC has crashed (it looses connection, I'm guessing through lack of bandwidth) which of course kills the guiding and everything else. I don't think (or can't find) that the EQDIR cable is USB3.0 only but it only seems to work directly in the USB3.0 port on the laptop. Oddly it seems to work fine in the USB2.0 hub (this one in fact) but again, only when plugged into the USB3.0 port (weirdness). It crashes when I have the lodestar and DSLR (Canon) plugged in too (just the lodestar and its fine, plug in the DSLR and thats when it goes and vice versa), hence why I think its probably bandwidth or power.

So I guess the question(s) are:

• Does anyone else have the HITEC ASTRO EQDIR, how do you use it and do you also have the USB 3.0 weirdness?
• How do you power (if at all) your cables and do you get bandwidth problems?
• Do you use a hub of any kind?

Finally, given I'm not getting out much in the evenings I'm going to try and image from the Coronado Solarmax during the day but will need a new imaging camera and most are (at least) USB3.0. What is everyone's recommendation around USB3.0 cables and hubs? I'm guessing this is just going to compound my issues :/

Anyway, clear skies everyone and thanks for any advice!

Cheers

Will

[PhotoGav]

Hello Will, good to see you 'back in the saddle'! I'm feeling rather responsible now that you have named and shamed me.... So, I must try and help...!

Funnily enough I have had major issues just recently with usb connectivity dropping out too. I am convinced that it was due to dropping temperatures and insufficient power arriving at the not powered separately Lodestar as it tended to be PHD that crashed first. I have just replaced my usb hub with a powered hub (usb 2). Despite the weather's best efforts, I have managed to use it a couple of times and have had absolutely no problems with crashing. So I think I can say that the problem is solved.

Therefore I reckon a powered USB hub could be your solution. I would plug it into the USB 2 port on your laptop and run everything into the hub.

Good luck and I look forward to seeing some Twisted Lip pics soon!

[Twisted Lip]

Haha, cheers Gav, I think I properly dropped you in it there!

Interestingly at the time you were writing that I noticed the hub I use is only rated down to 0 - its not that cold yet but I'm sure I've used it around that temp and clearly it may be affecting the cable.

Is your hub powered by your 12v pack or do you use it off the mains? Also, did you ever get the EQDir in the end or are you still going via the handset?

Cheers

Will

[Kropster]

The laptop may be running short of juice out the usb port.

Powering the hub might fix the problem.

[Twisted Lip]

The laptop may be running short of juice out the usb port.

Powering the hub might fix the problem.

Yes this was another thought, perhaps it just needs more power. I'm looking to get a new powered hub and perhaps a 12v supply so I can plug it into the pack rather than relying on mains.

[PhotoGav]

Is your hub powered by your 12v pack or do you use it off the mains? Also, did you ever get the EQDir in the end or are you still going via the handset?

I now power everything from the mains.

No, still using the handset. I have the EQDir in my FLO basket, but haven't got round to actually ordering yet!

[PhotoGav]

This is the hub that I bought from Maplin: http://www.maplin.co.uk/p/belkin-4-port-hi-speed-usb-20-mobile-hub-a92qy

[Guest]

The USB hub needs to be a powered one, I have my guide camera and DSLR plugged into a powered USB hub and that in turn into a 10 meter USB cable back to my obsy from outside in my back garden, into a USB port on my laptop and works fine, the mount is also plugged into the same powered hub at the mount and then that comes back inside on its own cable into the second USB port on my laptop.

All works fine, bit you can only have one piece of software connected to the scope at any one time, so if I have planetarium software running my scope, then I can't connect PHD guide to it, I have to disconnect the planetarium software and then connect PHD guide, this is normal from what I have read though

Hope this helps a little

Olly

[PhotoGav]

All works fine, bit you can only have one piece of software connected to the scope at any one time, so if I have planetarium software running my scope, then I can't connect PHD guide to it, I have to disconnect the planetarium software and then connect PHD guide, this is normal from what I have read though

That seems strange to me... I have CdC, APT, PHD2 & AT all connected to the mount simultaneously and they can each control the mount when required with no problem....

[IanL]

All works fine, bit you can only have one piece of software connected to the scope at any one time, so if I have planetarium software running my scope, then I can't connect PHD guide to it, I have to disconnect the planetarium software and then connect PHD guide, this is normal from what I have read though

Yes and no.  It all depends on the telescope driver.  The most basic design in ASCOM is that one mount driver can be controlled by one piece of software at a time, which is why you have to disconnect the planetarium before connecting PHD.

This can be overcome by using an ASCOM hub.  This basically allows multiple pieces of software to connect to it, and the hub connects to the driver (thus only one piece of software is actually connected to the driver itself). The hub then takes care of coordinating different commands from the various pieces of software and passing them to the scope driver.

Some drivers are ASCOM hubs in their own right (e.g. EQMOD for SkyWatcher mounts).  You just configure EQMOD with the mount connection details (COM port, etc.) and then choose EQMOD as the mount in the ASCOM chooser dialog from whichever piece of software you launch first.  You can then connect subsequent pieces of software and choose the EQMOD driver in the ASCOM chooser and it all works.

If you are using a non-hub mount driver, which I guess you are, then ASCOM includes a way to get around this limitation, the "POTH" driver that comes as standard with ASCOM (Plain Old Telescope Handset), described here:  http://ascom-standards.org/FAQs/POTH.htm

You launch the ASCOM chooser, pick "POTH" as the mount and then you'll need to configure it to connect to your existing telescope driver (making sure the scope driver has the correct settings, e.g. COM port, etc.)

You then need to configure each piece of software to connect via ASCOM (some planetaria have the option to connect directly to the mount which isn't going to work for this purpose).  When you launch the software and choose the option to connect to the mount, you'll then get the standard ASCOM chooser dialog and you pick POTH.  You connect each piece of software in the same way and then no more disconnect/connect hassle as they should work simultaneously.

One wrinkle to watch out for on certain Windows setups is that you need to make sure that each piece of software is running at the same level of privileges.  Lots of people have had problems where the second piece of software launched complains of errors like 'COM port in use'.  This is usually because one piece is running as a normal user and one is running as administrator and they try to launch different instances of the same driver since they can't communicate across privilege levels.  The normal cure if you get this is to right-click each piece of software and choose 'Run as Administrator' to start them up which forces them all in to the same privilege level.

You'll need to do a bit of research for your specific scope/driver/software to figure out the settings, but ask more specific questions on here if you get stuck and someone will be able to advise.

[James]

Whilst I can't help with some of the ASCOM related questions I have always found that I need a powered hub. I can set up some nights with the power not plugged in but eventually something cuts out - powering the hub fixes things.

One problem I found a while back with an older laptop was that whilst it had two USB ports the power supplied to each was different - the front port had 500mA supply but the rear one had only 350mA. This was all USB2 - as I understand it USB3 either requires (or is set up to provide) more power, 900mA?

James

[Twisted Lip]

Whilst I can't help with some of the ASCOM related questions I have always found that I need a powered hub. I can set up some nights with the power not plugged in but eventually something cuts out - powering the hub fixes things.

One problem I found a while back with an older laptop was that whilst it had two USB ports the power supplied to each was different - the front port had 500mA supply but the rear one had only 350mA. This was all USB2 - as I understand it USB3 either requires (or is set up to provide) more power, 900mA?

James

Hadn't thought of that either! I just assumed that the same level of power was being supplied to both, perhaps I should take a look. That would explain why the EQDIR only works when plugged into the USB3 port (even when through the USB2 hub and its not a USB3 device).

I now power everything from the mains.

No, still using the handset. I have the EQDir in my FLO basket, but haven't got round to actually ordering yet!

They're pretty good I have to admit so can recommend it. Took me a while to get working but I kept the drivers just in case anyone else needed them!

This is the hub that I bought from Maplin: http://www.maplin.co.uk/p/belkin-4-port-hi-speed-usb-20-mobile-hub-a92qy

Cheers chap, I'll take a look.

The USB hub needs to be a powered one, I have my guide camera and DSLR plugged into a powered USB hub and that in turn into a 10 meter USB cable back to my obsy from outside in my back garden, into a USB port on my laptop and works fine, the mount is also plugged into the same powered hub at the mount and then that comes back inside on its own cable into the second USB port on my laptop.

All works fine, bit you can only have one piece of software connected to the scope at any one time, so if I have planetarium software running my scope, then I can't connect PHD guide to it, I have to disconnect the planetarium software and then connect PHD guide, this is normal from what I have read though

Hope this helps a little

Olly

I'm thinking you're right, power may be the way forward. Although its very interesting what you and Ian are saying about the mount control. Like Gav I have hooked up CdC, APT and PHD and don't disconnect any of them, just let them get on with it. While they were all plugged into different ports there didn't seem to be an issue but I am using ASCOM with the SW NEQ6 so perhaps that is it.

Ian - I'll definitely look more into that, certainly wasn't something I have considered.

Cheers all

Will

[Guest]

That seems strange to me... I have CdC, APT, PHD2 & AT all connected to the mount simultaneously and they can each control the mount when required with no problem....

Oh ok, there must be something I am missing then....apologies for the incorrect information

Olly

[Guest]

Oh ok, there must be something I am missing then....apologies for the incorrect information

Olly

Yes I have just read the post from Ian, I remember reading something about an Ascom hub driver, I only use the basic one, so,that is where the mis information came from

Apologies again..

Olly

[PhotoGav]

Ah interesting about the different styles of ASCOM driver / hub - that has to be it. What mount are you using Olly? I can't work it out from your sig! I'm using a SW HEQ5 with EQMOD and I guess the ASCOM hub technology - that must be why multiple software connections work fine for both me and Will.

[Guest]

Ah interesting about the different styles of ASCOM driver / hub - that has to be it. What mount are you using Olly? I can't work it out from your sig! I'm using a SW HEQ5 with EQMOD and I guess the ASCOM hub technology - that must be why multiple software connections work fine for both me and Will.

Mine is a Meade LX90 on a wedge, using ascom platform and the meade autostar 497 driver, for telescope control, but like I say I am just using the basic driver, I must try the hub version, although really I don't need it to communicate with more that one piece of software at a time, what I have works ok for my set up.

Regards

Olly

[PhotoGav]

If it works, don't touch it!

[Twisted Lip]

If it works, don't touch it!

Haha yes agreed, change is where problems await!

Will

[Kropster]

I get very confused about all the Ascom stuff.....When I have the mount working with Stellarium and PHD I think myself very lucky and try to remember how I managed to achieve it, so I can do the same again in three months when we get another clear night!

[uhb1966]

Tip - try to use cables that are just long enough - i sometimes run into trouble when using long usb cables (more than 2 meters) outside at night

[Twisted Lip]

Tip - try to use cables that are just long enough - i sometimes run into trouble when using long usb cables (more than 2 meters) outside at night

Thats ok but unfortunately my scopes are a bit too far away from the laptop which is why I usually use 10m+ cables but I definitely think you're right, the longer they are the more problems are introduced. I'm hoping a powered hub might resolve it.

[Guest]

Thats ok but unfortunately my scopes are a bit too far away from the laptop which is why I usually use 10m+ cables but I definitely think you're right, the longer they are the more problems are introduced. I'm hoping a powered hub might resolve it.

A powered hub is an absolute must when using USB cables longer than 3 to 4 meters

Olly

[uhb1966]

5m is the max spec length for usb 20

[uhb1966]

But its going to be difficult to put a powered hub in the middle, after 5m, where it should be >_<

[Kropster]

On long runs, use active usb cables... they boost the signals to cope with the cable length.

I have a 12m one in use.