subject: Usb Cables - What Do Usb Cables Do? [print this page] USB cables (Universal Serial Bus) are cables purpose built for use with USB hardware. Such cables will have any combination of the appropriate male and female ends, in any of the varying sizes and types as defined by the USB specification. The USB specification states that a USB cable can be no longer than 5 feet due to signaling needs. USB specification requires no more than 26ns (nanoseconds) of delay between devices and the USB hub. USB version 1.x and 2.x cables employ twisted pairs for the wires to reduce crosstalk and noise. USB version 3.x cables add shielding to the pairs.
USB cables are a standard when it comes to connecting serial devices in a way that is networked in nature. The USB standard defines three distinct devices, which are functions, hosts and hubs. The host is the initiative device, such as a PC. Only a single host can exist in your network. The functions are dumb devices such as mice, keyboards and printers. The hubs are perceived as multi-port repeaters and they act like distributing devices within the serial network. The maximum speed for a USB network is 12 megabits per second or Mbps, using a STP cable. There is also a possibility for UTP, but the limit here is only 1.5 megabits per second.
There are essentially two different types of USB cables. The standard type of USB cable possesses an A-series connector and is used for 12 megabits per second. It has a single pair of 20-28 AWG wires for the power and another 28 AWG pair of twisted wires for the data. The cable is STP capable due to having both a shield and a jacket. The other type of USB cable is a 1.5 megabits per second version, which features a B-type connection. This cable is typically only used for sub-channel applications.
USB cables are used for a wide variety of different purposes, though the cables are largely interchangeable. The USB connector is almost always the same, but the opposite end of the connection depends on what the USB cable is supposed to connect to, such as a portable device. Digital cameras, multimedia cellular phones, palm pilots and blackberries are all examples of USB cables that you can use for various purposes. Some portable gaming platforms like the Nintendo DS and the Playstation Portable (PSP) may also use USB cabling for specific purposes.
