Communications through a USB hub

[Boilermaker10]

I have a pair of FuTek USB210 devices that function perfectly when connected directly to the computer, but have significant problems if I try to plug them into the Plugable 10-port USB hub.  I have a lot of instruments that I need to connect, and I'm concerned that I won't be able to talk to them through the USB hub.  The devices in question come from a number of manufacturers (not all of which want to play nice with LabView) but almost universally are using serial connections to output that I've turned to USB somewhere along the line. 

Will the hub be a problem?  If so, how can i communicate with other devices through the hub?

[altenbach]

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@Boilermaker10 wrote:

... but have significant problems if I try to plug them into the Plugable 10-port USB hub.

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Can you describe the "significant problems" in detail?

[LuisMontoya]

maybe the USB Hub has not enouth Power for all instrument.

Try puting power to USB Hub

[Boilermaker10]

It's an externally powered hub, and drawing power perfectly fine.  I don't think this is the issue.

[Boilermaker10]

"Significant problems"-- the example code provided by FuTek couldn't find the USB210 devices.  A request for the device handle returned a 0, or unsuccessful.

[altenbach]

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@Boilermaker10 wrote:

"Significant problems"-- the example code provided by FuTek couldn't find the USB210 devices.  A request for the device handle returned a 0, or unsuccessful.

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That seems like important information :o! Does it work with other software?

[Boilermaker10]

The FuTek devices will run correctly if plugged directly into the computer (well-- sometimes.  There appears to be a gremlin that causes them to have other, irregular errors...but I was always taught 'one problem at a time'.)  So far as I can tell, the hubs allow normal communication with other devices, as well.

On an unrelated note: I like your job descriptor, sir altenbach.

[PhillipBrooks]

I looked at the Plugable 10 port hub and it indicated that the power supply is rated for 2.5A at 5VDC. 

A low power USB port will provide ~500mA, I think a high power port will provide ~900mA.

If you fully load the hub, there would only be ~ 250mA per sensor. The Futek sensor looks like it provides excitation voltage as well as A/D etc... Futek does not publish current specs for the sensor. You might want to contact them and ask about a hub for the number of devices you are connecting.

Try plugging in one or two sensors to the hub, then add from there.

[Boilermaker10]

I can accept the FuTek devices needing to plug directly into the PC.  My question is more this: will I need to modify the VIs written for other sensors (most of which are not yet online) if the VIs were written under the assumption that they would be plugged directly into the computer?  Is there some special programming consideration, or is LabView smart enough to work with the devices normally?

[Hooovahh · Accepted solution]

You shouldn't have to worry.  The drivers were likely written with some DLL that finds devices, or a VISA resource that is found.  These layers of the protocal are taken care of for you and your don't need to care where the device is plugged in, only that Windows can detect it (device manager is a good place to start)