Archive for the ‘USB’ Category

Connecting peripherals with USB

Saturday, November 14th, 2009

Connecting peripherals with USB.

Because USB connections are hot-swappable, you can attach or remove peripherals without shutting down your computer.

A standard USB cable features two different kinds of connectors. A USB Type A connector plugs into a host device, such as your PC. The USB Type B connector plugs into the peripheral. Having two different types of connectors helps to prevent accidental loops.

To add more USB devices than your computer has USB connectors, you need a device called a USB hub. A hub provides additional connectors for your peripherals. Some USB devices (especially keyboards) feature built-in hubs, so you can plug yet another USB device (such as a mouse) into them.

You can plug hubs into other hubs to provide more connections. Each new layer of hub and cable is called a tier. USB supports a maximum of 5 tiers with up to 127 attached devices. Every other hub must be externally powered in order to supply enough power to attached peripherals.

A hub can also add additional distance between your PC and a peripheral. Each USB segment can be up to 5 metres (16.4 feet). Because USB supports up to 5 tiers, you can put peripherals a maximum of 25 metres (82 feet) from your PC.