Z2, Power Media Dock, Devices that don't like USB Hubs

So in my exploration of the Z2 as my new laptop, something popped up that hadn't occurred to me earlier.

I have two devices that really, really don't like working on hubs - even powered hubs - specifically, an Epson 2450 flatbed scanner and Datacolor Spyder3Elite colorimeter.

Given the dearth of ports on the Z, even with the PMD attached, I'm tight on options. The bigger question, though, is will these devices play nicely with the USB 2.0 port on the PMD itself - or would that constitute being on a hub?

They -do- work on the ports built into my current laptop (an ASUS), but frankly, I'm not sure if those ports are true direct USB ports or not. As I understand it, a lot of USB ports nowadays are, in fact, linked to a hub inside the chassis.

My technical understanding of the problem here and the hardware involved is a bit limited. Could anyone help shed some light on this?

Thanks in advance!

P.S. I know that I could replace the flatbed, but I'm really loathe to, as tossing a functional piece of hardware just pains me. Plus, I'm still left with the question of the Datacolor. As the USB 3.0 port on the Z will be taken by the PMD connector, using the remaining on-body port for the datacolor would preclude me leaving my wireless mouse adapter in there, which undermines the whole advantage of the plug-n-forget interface that's helpful given how frequently this machine moves in and out of my office.

 

A standard USB port will provide up to 500mA to the device that is attached. Many USB-only devices (no AC adapter) require that 500mA in order to function.

When you connect a stand-alone "bus powered" USB hub (typically 4-port) to that USB port, that 500mA gets split up: 100mA to each of the 4 ports, and 100mA to power the hub itself. That means devices that require 500mA (probably including your scanner and colorimeter) will not work.

There are "self-powered" hubs which include an AC adapter for the hub itself. They're bulkier, but they get extra power from the AC adapter in order to provide full 500mA to all ports.

As the Z2's PMD itself requires its own AC adapter, the USB ports on the PMD should all be able to provide full 500mA to power your devices. But if you need more USB ports, consider getting a self-powered USB hub.

 

You could switch to a bluetooth mouse to free up that USB port.

 

Problem is, I haven't been able to find a powered hub with enough oomph to provide 500mA across all of its ports. For example, the one I have now is an 8-port hub with a 2000mA power supply, which means that at max capacity it's only really providing 250mA to each port. Do you know of any that have a robust enough power supply to actually get 500mA to each port at full load?

Edit: Sure enough, when I remove enough devices from the hub to provide ample power, the scanner works.

 

Then buy two hubs and distribute your devices between them?

 

Unfortunately, from what I've been able to see, smaller hubs have respectively smaller power supplies, and remain similarly underpowered. If you know a model that doesn't suffer from this, I'd happily try it!

 

I would buy an USB hub and in local electronic shop bigger AC and redo the connector - it shouln't hurt, if the polarity is right.

 

Doesn't mean the hub can handle it of course.

The D-Link DUB-H7 has a 3A supply. Find it on Amazon, etc.

 

Thanks Vogel - I'll give that a shot