Unsolved
This post is more than 5 years old
1 Rookie
•
120 Posts
0
86781
January 20th, 2008 17:00
Active USB 2.0 Repeater Cable vs USB 2.0 powered hub
Hi,
I need to be able to print to two printers both 7 mtrs away from my Dimension 9150. Which of the following is best:
1 x 5m USB2.0 cable to USB 2.0 powered hub then 2 x 2m USB2.0 cables to each printer.
or
2 x 5m active repeater USB 2.0 cables from desktop with a 2m USB2.0 extension to each printer.
Help much appreciated.
Zippy
Dell Dimension 9150 running XP MCE
Dell 1720db Laser printer
Epson Stylus RX620
No Events found!


85rx-7se
326 Posts
0
January 20th, 2008 17:00
external USB devices which the main usb ports can not
provide. It will not overcome the inherent limitations of
the USB 2.0 specifications .. USB may not work properly
at lengths of over 15 meters
http://en.wikipedia.org/wiki/USB
The maximum length of a standard USB cable is 5.0 meters (16.4 ft). The primary reason for this limit is the maximum allowed round-trip delay of about 1500 ns. If a USB device does not answer to host commands within the allowed time, the host considers the command to be lost. When USB device response time, delays from using the maximum number of hubs and delays from cables connecting the hubs, host and device are summed, the maximum delay caused by a single cable turns out to be 26 ns [9]. The USB 2.0 specification states that the cable delay must be less than 5.2 ns per meter, which means that maximum length USB cable is 5 meters long. However, this is also very close to the maximum possible length when using a standard copper cable.
Using USB devices over a greater length require hubs or active extension cables. Active extension cables are bus-powered hubs equipped with two maximum length standard USB cables. USB connections can be extended to 50 m (160 ft) over CAT5 or up to 10 km (6.2 mi) over fiber by using special USB extender products developed by various manufacturers.
In practice, some USB devices may work with longer cable runs than 5 meters, if the number of hubs between the host and the device is less than the maximum number allowed by the USB standard. However, using a longer cable lowers both the signal quality and the voltage provided by the USB bus below the specification tolerance limits. This may prevent USB devices from working properly or even from working at all.
85rx-7se
326 Posts
0
January 20th, 2008 17:00
And it will be less costly than the repeater cables.
Zippy42
1 Rookie
•
120 Posts
0
January 20th, 2008 17:00
Zippy42
1 Rookie
•
120 Posts
0
January 20th, 2008 18:00