Use of a A to A USB Cable ?

[Patrick]

I buy a PC magazine today and it comes with a supplementary USB Cable (A to
A).

I just wonder in what circumstances should I use this cable ? So far as I
know, we should use a A to B USB Cable to connect XP to a device.

Does it mean that the cable can be used to connect two XP workstations so
that we can transfer files between them ?

Thanks

 

[Paul]

I buy a PC magazine today and it comes with a supplementary USB Cable (A to
A).

I just wonder in what circumstances should I use this cable ? So far as I
know, we should use a A to B USB Cable to connect XP to a device.

Does it mean that the cable can be used to connect two XP workstations so
that we can transfer files between them ?

Thanks

To connect two computers together, you use one of these.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812200198

There is a chip in the center of the cable. It isolates the two
USB networks from one another. Queues are kept in either direction,
inside the chip, and packets are passed from one side of the
chip to the other. The most important item, is the software that
comes with the device. It supports file transfer, or alternately,
provides a TCP/IP stack for more flexibility. It is sort of a
"laplink" cable, only for USB.

*******

When you see a cable, with a chip blob near one end, and using
USB-A and USB-B connectors, that is an active extender cable.
The blob on the end of the cable, is actually a one port hub,
used to electrically buffer the USB signal. The USB standard
places a limit on the overall delay, so you cannot use too
many of those cables in a row. An active extender cable is usually
the maximum length allowed, which is 5 meters. So that cable
will be a bit different, than the more non-standard one above.

*******

In the chart on this page, USB-A to USB-A is rated "non-standard".
I cannot think of a use for it, right off hand.

http://en.wikipedia.org/wiki/Usb

Cables |
| Plug Micro-B Micro-A Mini-B USB-B USB-A
---------+----------------------------------------------------------
Plug |
USB-A | OK NS OK OK NS <---
USB-B | X NS X X
Mini-B | X NS X
Micro-A | OK X
Micro-B | X

HTH,
Paul

 

[Paul]

To connect two computers together, you use one of these.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812200198

There is a chip in the center of the cable. It isolates the two
USB networks from one another. Queues are kept in either direction,
inside the chip, and packets are passed from one side of the
chip to the other. The most important item, is the software that
comes with the device. It supports file transfer, or alternately,
provides a TCP/IP stack for more flexibility. It is sort of a
"laplink" cable, only for USB.

*******

When you see a cable, with a chip blob near one end, and using
USB-A and USB-B connectors, that is an active extender cable.
The blob on the end of the cable, is actually a one port hub,
used to electrically buffer the USB signal. The USB standard
places a limit on the overall delay, so you cannot use too
many of those cables in a row. An active extender cable is usually
the maximum length allowed, which is 5 meters. So that cable
will be a bit different, than the more non-standard one above.

*******

In the chart on this page, USB-A to USB-A is rated "non-standard".
I cannot think of a use for it, right off hand.

http://en.wikipedia.org/wiki/Usb

Cables |
| Plug Micro-B Micro-A Mini-B USB-B USB-A
---------+----------------------------------------------------------
Plug |
USB-A | OK NS OK OK NS <---
USB-B | X NS X X
Mini-B | X NS X
Micro-A | OK X
Micro-B | X

HTH,
Paul

I did find another flavor. This is a passive extension cable.

http://www.provantage.com/fullsize/TRPA166.jpg

I guess one is a USB-A male and the other is a USB-A female.
Pretty hard to make an extension with a USB-A and a USB-B
(My bad)

The same kind of connectors would be used on the active extension
cable as well. This is an example of a 5 meter active extension
with one port hub chip on one end. Some of these suck, and don't perform
their intended function (some cannot be chained together, and work).

http://c1.neweggimages.com/NeweggImage/productimage/12-816-021-01.jpg

I thought of one place where a USB-A to USB-A (same on both ends)
might be used, but on checking now, I cannot find examples any more.
The manufacturers all seem to be playing by the rules.

Paul

 

[Patrick]

Dear Paul,

The USB Cable is of 1m in length and both ends are USB-A Male. In this way,
I believe that it is a non-standard one and is of no use to me.

Thanks again
Patrick

 

[Patrick]

Dear IceMan,

Thank you for your advice.

You have mentioned "I would never do that ....". Does it mean to connect to
XP workstations ?