Max cable length from mount to PC?

[lifeofbrian]

I would like to use my PC to connect to my AP mount(yet to purchase), I was wondering if there would be an issue with length. I have a 10m ethernet cable, and can get a 10m USB cable with signal amplification. The mounts I'm looking at are the Skywatcher AZ-GTI and Star Adventurer.

Brian.

[Craig a]

I tried a powered 10m usb repeater, gave me issues with guiding, I think the distance was too much and the guiding commands couldn’t keep up, went down to a 3m usb cable and the problem went away 

Edited September 8, 2020 by Craig a

[Seelive]

I've also tried a USB repeater (15m) and that didn't work either when trying to guide. It all works fine with a standard 5m USB cable.

[lifeofbrian]

3 hours ago, Craig a said:

I tried a powered 10m usb repeater, gave me issues with guiding, I think the distance was too much and the guiding commands couldn’t keep up, went down to a 3m usb cable and the problem went away 

 

1 hour ago, Seelive said:

I've also tried a USB repeater (15m) and that didn't work either when trying to guide. It all works fine with a standard 5m USB cable.

I just found an article saying that USB 2.0 has better range than 3.0, what did you guys use?

[JamesF]

I've never tried it, but I'm surprised that a longer active USB cable would cause problems with guiding if that's all it is being used for (and it's a decent quality cable).  It's not as though it takes significantly longer for the signals to travel 10m than 3m in comparison to guiding.

On the other hand, I'd not be entirely surprised if there were problems if the single cable were also being used for downloading images from the imaging camera as well.  I can see there might well be some bus contention there that might be unhelpful.  I have a computer on the pier and still run a separate cable for the imaging camera to try to minimise the amount of fighting over bandwidth that goes on.

11 minutes ago, lifeofbrian said:

I just found an article saying that USB 2.0 has better range than 3.0, what did you guys use?

The USB spec allows a longer cable length for USB2 than USB3, but plug a USB2 cable into a modern USB3 camera with a fairly large frame size and download times will probably be quite noticeable.

James

[MarkAR]

I've sorted mine out with a Raspberry Pi and 20m ethernet cable, not sure how I would go about connecting an AZ-GTI or Star Adventurer to the RPi. 

[Seelive]

6 hours ago, lifeofbrian said:

 

I just found an article saying that USB 2.0 has better range than 3.0, what did you guys use?

The guide camera and mount are USB2 as is the USB hub at the mount. The cables are all standard USB2 but the 5m cable plugs into a USB3 port on the PC (no other choice).

[Xsubmariner]

LifeofBrian - I use “Startech” or “Lindy” USB hubs and active cables with my imaging setups and have no problem with equipment connectivity over 10M. Any USB3.0 port on a PC should be backward compatible to USB2.0 

In your post you say AP mount then later state the mounts you are considering, by AP were you implying AstroPhotography Mount. If that is so, may I recommend you look to acquiring an EQ Mount as opposed to AZ Mount.

[MarkAR]

USB2 has greater range than USB3 but USB3 is faster. Getting longer range with USB3 means you have to link up powered cables and they don't always work for astrophotography. I used to use a powered 20m USB2 hub but it didn't like the USB3 guide Cam being plugged in at the same time so had to plug that in to the laptop separately and sit outside by the scope for it all to work.

[DaveS]

Stick PC and RDP via WiFi?

[lifeofbrian]

7 hours ago, Xsubmariner said:

LifeofBrian - I use “Startech” or “Lindy” USB hubs and active cables with my imaging setups and have no problem with equipment connectivity over 10M. Any USB3.0 port on a PC should be backward compatible to USB2.0 

In your post you say AP mount then later state the mounts you are considering, by AP were you implying AstroPhotography Mount. If that is so, may I recommend you look to acquiring an EQ Mount as opposed to AZ Mount.

It's ok the az-gti mount has firmware to use as eq with an eq wedge. I'll look for those brands, there are so many obscure Chinese ones out there to sift through. Thanks.

[PlankWithANailIn]

Lots of talk about the fundamental limits of USB without addressing the more important issue that you can't connect to either mount using USB. 

You can't connect to the AZ-GTI mount using USB or a network cable you have to use a USB to serial port converter.

I don't own the star adventurer but the manual seems to suggest that its usb port is for power and firmware updates not controling the mount https://inter-static.skywatcher.com/downloads/StarAdv_manual_150722V2_updateds.pdf. It doesn't look like you can control that mount externally at all.

I use a small lenovo thinkcentre mini PC strapped to my tripod and use that to control my AZ-GTI via a cable I made myself (The lynx ones on FLO are comedy priced at £30 for a £5 USB/Serial converted and 10p worth of cable!). I found the WI-FI connection to be too unreliable. I power the mount and PC from an external plug socket on my garage and use a powerline adapter to connect the Lenovo  to the home network via the power cord. I then use remote desktop to control the mount and cameras from my laptop in the living room.

Edited September 22, 2020 by PlankWithANailIn

[04Stefan07]

As far as I know, I used to use an active 5m USB extension cable. I ditched all that long, long ago and RDP to a computer that houses the lot. If I don't have WiFi and out in the field then I can run an Ethernet cable which you can do up to 100m!