USB limits of pc's

  • Thread starter Thread starter -keevill-
  • Start date Start date
K

-keevill-

I always believed that one of the strengths of USB devices was the ability
to 'daisy chain' many devices into the pc using USB extenders. However I
notice that I am unable to connect many without them failing because of lack
of power. For example, I have the following devices connected to my 4 USB
port PC. Scanner, USB microphone, Pocket PC, iPOD. I occasionally 'lose' one
or other of the devices and I have to reboot.
I also have a USB camera I would like to attach and a SD card reader but
they cannot be seen if I attach them.
I have bought a USB extender with a separate power supply for it but this
makes no difference.
Is there something I can do ?
 
Cari (MS-MVP) said:
Buy a powered USB hub.
Click to expand...

Um, the OP wrote and I quote:

"I have bought a USB extender with a separate power supply for it but this
makes no difference."

Alias
 
-keevill- said:
I always believed that one of the strengths of USB devices was the
ability to 'daisy chain' many devices into the pc using USB extenders.
However I notice that I am unable to connect many without them failing
because of lack of power. For example, I have the following devices
connected to my 4 USB port PC. Scanner, USB microphone, Pocket PC,
iPOD. I occasionally 'lose' one or other of the devices and I have to
reboot.
I also have a USB camera I would like to attach and a SD card reader
but they cannot be seen if I attach them.
I have bought a USB extender with a separate power supply for it but
this makes no difference.
Is there something I can do ?
Click to expand...

There was a time that XP did not like to have both a scanner and camera
connected simultaneously - TWAIN issues???

Check each root hub, power management tab, and verify that the checkbox
"allow computer to turn off device to save power" is not checked.
Otherwise, you might get a voltmeter and your mainboard manual and check
the voltage to the USB when it is under a typical device load.
 
USB can provide 500 mW to each port at the computer. Thus
the first hub only has 500mW available unless you use
powered hubs that will continue to provide the full 500mW to
each port on each hub in the daisy-chain.


--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm



|
| | >I always believed that one of the strengths of USB
devices was the
| >ability to 'daisy chain' many devices into the pc using
USB extenders.
| >However I notice that I am unable to connect many without
them failing
| >because of lack of power. For example, I have the
following devices
| >connected to my 4 USB port PC. Scanner, USB microphone,
Pocket PC,
| >iPOD. I occasionally 'lose' one or other of the devices
and I have to
| >reboot.
| > I also have a USB camera I would like to attach and a SD
card reader
| > but they cannot be seen if I attach them.
| > I have bought a USB extender with a separate power
supply for it but
| > this makes no difference.
| > Is there something I can do ?
| >
|
| There was a time that XP did not like to have both a
scanner and camera
| connected simultaneously - TWAIN issues???
|
| Check each root hub, power management tab, and verify that
the checkbox
| "allow computer to turn off device to save power" is not
checked.
| Otherwise, you might get a voltmeter and your mainboard
manual and check
| the voltage to the USB when it is under a typical device
load.
|
|
 
Extender allows you to "extend" the distance the USB hubs can be. Powered
USB hubs will help by providing additional power to the USB ports on that
hub.
 
Jim Macklin said:
USB can provide 500 mW to each port at the computer. Thus
the first hub only has 500mW available unless you use
powered hubs that will continue to provide the full 500mW to
each port on each hub in the daisy-chain.
Click to expand...

I believe that I bought a powered hub. It's a small 4 port mini hub with an
ac adaptor which purports to be its power supply.Therefore, do I have a
device which is being recommended here?
I confirm that when using this, it makes no difference.
 
-keevill- said:
I believe that I bought a powered hub. It's a small 4 port mini hub with
an ac adaptor which purports to be its power supply.Therefore, do I have a
device which is being recommended here?
I confirm that when using this, it makes no difference.
Click to expand...
I suspect the device you have is not powering the ports, but only the status
lights.
A powered hub will be heavy, and generally not small. I am using a Belkin
8-port powered USB-2
hub, and I can connect 8 devices (scanner, printer, game controller, memory
card reader, ATI remote control, etc) to this and they all work fine.

Bobby
 
Well Cari is yet another "Dumb Blond needs USB help .."

If you see Tipex marks on screen, you can reliably assume that a dumb
blond was using it!!!
 
Oh 'Cheesez'! Something else to buy!


NoNoBadDog! said:
I suspect the device you have is not powering the ports, but only the status
lights.
A powered hub will be heavy, and generally not small. I am using a Belkin
8-port powered USB-2
hub, and I can connect 8 devices (scanner, printer, game controller, memory
card reader, ATI remote control, etc) to this and they all work fine.

Bobby
Click to expand...
 
Back
Top