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UPS USB chaining?
Authored by: sben on Feb 10, '04 11:40:40AM

Does anyone happen to know if one can connect a UPS to an unused USB port on an Apple keyboard? I need a USB hub, I know, but don't have one yet, and would like to be able to use the UPS in the meantime.



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UPS USB chaining?
Authored by: the1truestripes on Feb 10, '04 02:57:32PM

Yes, the Apple keyboard is a USB hub, it just doesn't have many ports. If you are looking for a USB hub you might try looking at Free After Rebate they have them from time to time. It'll cost you shipping though (unless you manage to find enough free items all in one place to qualify for free shipping!). Good luck.

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UPS USB chaining?
Authored by: sben on Feb 10, '04 07:21:09PM

Thanks for the rebate link; I'll check that out.

Slightly defensively, yes, the Apple keyboard is a USB hub, but I was wondering if there are any issues the way (Apple claims) there are with running Apple speakers through -- the keyboard doesn't support whatever the audio-over-USB spec is.

So: Is there some kind of funky UPS-over-USB functionality that most Apple keyboards don't provide? Or am I just worrying about nothing?



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UPS USB chaining?
Authored by: ducasi on Feb 11, '04 03:53:20AM

APC say you should plug their UPSes directly into a USB port on the computer, rather than though a hub.

I'm not sure why... Perhaps it's to ensure you're not plugging it in through an unprotected mains-powered USB hub. Or maybe there's another reason... Try it and see what happens.



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UPS USB chaining?
Authored by: theocrates on Feb 11, '04 09:19:28AM

I've never been certain why APC says one should plug the UPS directly into the computer instead of a USB hub. I suspect there is some obscure technical reason; but hypothetically there is no reason why you couldn't plug in the UPS via a hub, as long as the hub is itself plugged into the Battery Backup side of the UPS.

I ran tests just last night, pulling the plug on the UPS unit: battery power kicked in instantly and the PowerChute software displayed an alert box a few seconds after that. The software also "gracefully" shut down my computer when the battery reached the limit I had set in the software preferences. I successfully repeated this test several times.

So, it appears that the UPS unit does indeed function just fine through a (powered) USB hub when power is cut; and the PowerChute software also kicks in just fine if you're running it, even though APC says it is not fully compatible (what in particular is not fully compatible about the software, I don't know).

Incidentally, I have a Backups Pro 500, which has my 533 MHz G4, a 19" CRT monitor, an Aiport Extreme Base Station, and a 4-port USB hub plugged in to the Battery Backup side. The UPS's USB cable is plugged into that hub.



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UPS USB chaining?
Authored by: AIVAS on Feb 10, '04 08:20:49PM

The USB hub in the keyboard is a passive device. It is powered by the computer. It has no power supply of it's own. Therefore the keyboard (and usually the mouse since people usually plug it in to the keyboard) derive their power from this hub. There is little power left. I would recommend not plugging anything into the keyboard hub unless it is a self-powered (active) USB hub.

When selecting a USB hub, chose one that comes with a power adapter.



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