USB Hub question

[George Gearless]

Not sure if this is the right place to ask, but here goes.

I have an older laptop that I'm thinking of using for imaging. It only has two USB2 ports. For the most part I prefer using a mouse rather than the finger pad. So that leaves one USB port for cameras and 'other stuff'.

Let's just for arguments sake say that I have a main camera, a guide camera, a focuser and mount control. If I put those four into a USB-hub which is connected to the single USB2 port, what will happen?

A. Nothing. The single port will not be able to distinguish what signal goes to what because it's all jumbled together in the hub. It's like playing four different television programs at the same time on one screen.

B. Technically, it'll work. But because you're cramming a data-stream meant for four ports into one, you'll experience 'lag' during big data transfers. But it will get there eventually. As fast as the USB2 will allow. 

C. It'll be fine. I'm surprised you're even asking.

 

Anyone got any experience with this?

 

Georg

 

[RayD]

15 minutes ago, George Gearless said:

Not sure if this is the right place to ask, but here goes.

I have an older laptop that I'm thinking of using for imaging. It only has two USB2 ports. For the most part I prefer using a mouse rather than the finger pad. So that leaves one USB port for cameras and 'other stuff'.

Let's just for arguments sake say that I have a main camera, a guide camera, a focuser and mount control. If I put those four into a USB-hub which is connected to the single USB2 port, what will happen?

A. Nothing. The single port will not be able to distinguish what signal goes to what because it's all jumbled together in the hub. It's like playing four different television programs at the same time on one screen.

B. Technically, it'll work. But because you're cramming a data-stream meant for four ports into one, you'll experience 'lag' during big data transfers. But it will get there eventually. As fast as the USB2 will allow. 

C. It'll be fine. I'm surprised you're even asking.

 

Anyone got any experience with this?

 

Georg

 

Data wise will be fine. 

The one thing you will probably want to do is make sure it is a powered hub as your laptop hub may struggle to provide the power needed to run all the devices, a couple of which are USB powered.

Edited August 3, 2020 by RayD

[George Gearless]

2 minutes ago, RayD said:

Data wise will be fine. 

The one thing you will probably want to do is make sure it is a powered hub as your laptop hub may struggle to provide the power needed to run all the devices, a couple of which are USB powered.

Ahh, hadn't thought of the power issue. Good catch.

 

Thanks

[Adam1234]

Keep an eye on your camera if you have that plugged into the USB hub. I don't know what camera you're using but I'm using the ZWO ASI1600mm Pro, and discovered an issue recently where it kept disconnecting when plugged in to the hub, but it's absolutely fine if plugged directly to the laptop. The weird thing was that the guide scope and filter wheel were connecting fine, even though they connect to the USB hub via the camera. 

[rob_r]

I'm going with C. I think the key word here is 'theoretically'. So yes in theory, you could add some latency in the transfers due to cramming all the data into a single path but such latency would be a millisecond or shorter. A mouse has a very low data rate in any case and your laptop may have it's own internal hub anyway under the hood. As RayD suggests, just make sure it is powered. I remember the days of when USB first came out with these hubs, only to find those hubs losing power by having multiple devices plugged in and losing data that way. Non powered hubs should only be used for devices with a low power draw.

[George Gearless]

14 minutes ago, Adam1234 said:

Keep an eye on your camera if you have that plugged into the USB hub. I don't know what camera you're using but I'm using the ZWO ASI1600mm Pro, and discovered an issue recently where it kept disconnecting when plugged in to the hub, but it's absolutely fine if plugged directly to the laptop. The weird thing was that the guide scope and filter wheel were connecting fine, even though they connect to the USB hub via the camera. 

I'll be using a ASI ZWO 385MC. I'll keep the issue in mind. Thanks for the 'warning'.

Maybe I'll plug the mouse into the hub instead and the main camera into the one USB port.

[Adam1234]

20 minutes ago, George Gearless said:

I'll be using a ASI ZWO 385MC. I'll keep the issue in mind. Thanks for the 'warning'.

Maybe I'll plug the mouse into the hub instead and the main camera into the one USB port.

It might not cause you any issues going camera into usb hub but worth bearing in mind that if you do get connection issues it's probably that

[Astrosharkey]

I used a powered hub with my guide camera, filter wheel, mount control and focus unit and my main imaging camera on a seperate USB lead to avoid conflicts, If I had both cameras on the hub it would cause issues.

[Waldemar]

In fact your 2 computer USB ports are on an internal hub already. 
The best way to go at this, is to get a 12 volt powered USB hub and a power hub mounted on top of your telescope.
So you will only have 1 USB and 1 power cable coming down from the mount.
In that way there won't be cable clutter or drag.

edit: StarTech has a very good 12V USB hub 

Edited August 3, 2020 by Waldemar