In computing, a Docking station or port replicator or dock provides a simplified way of "plugging-in" an electronic device such as a laptop computer to common peripherals. Because a wide range of dockable devices—from mobile telephones to wireless mice--have different connectors, power signaling, and uses, docks are not standardized and are therefore often designed with a specific make and model of a device in mind.
A dock can allow some laptop computers to become a substitute for a desktop computer, without sacrificing the mobile computing functionality of the machine. Portable computers can dock and undock hot, cold or standby, depending on the capabilities of the system. In a cold dock or undock, one completely shuts the computer down before docking/undocking. In a hot dock or undock, the computer remains running when docked/undocked. Standby docking or undocking, an intermediate style used in some designs, allows the computer to be docked/undocked while powered on, but requires that it be placed into a sleep mode prior to docking/undocking.
Docking stations can be broadly split up into four basic varieties.
Port replicators (also called passthroughs) are functionally and logically identical to a bundle of extension cables, except that they are plugged in and unplugged together through the docking port. Some also include electrical adaptors to change from one pinout to another (e.g., Micro-DVI to normal DVI connector.)
A breakout dock is conceptually a breakout box in the form of a dock. It is an extension to a typical port replicator in that it not only replicates existing ports already on the computer, but also offers additional ports. Modern computers most often accomplish this by using a special, often proprietary, connector that consolidates the signals from many concealed traces from onboard external buses into one connector. As such, the dock can offer a greater number of ports than is physically present on the computer. This allows the basic unit to have fewer physical ports while still allowing users a way to access to the full range of features of its motherboard.
Most companies that produce laptops with such breakout ports also offer simpler adapters that grant access to one or two of the buses consolidated in them at a time.
Similar to a breakout device, some docking stations produce multiple connections from one port, only instead of extracting them from internal chipsets, they create them inside the dock using converters. They are functionally identical to a hub with various converters plugged in. Typically USB-based, they incorporate a range of converters such as USB display adapters, audio chipsets, NICs, storage enclosures, modems and memory card readers connected through an internal USB hub to give the host computer access to extra connections it did not previously possess. Simpler “docking stations” consist of nothing more than a hub inside a stand.
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