Automated test platforms are designed to check chips make sure they work, and if so, how well (usually how fast) they perform. Automated test platforms are usually specialized as either memory chip testers, digital logic chip testers, or analog chip testers, though some of the more sophisticated testers can deal with more than one of these groups. Testers consist of a test control unit or panel and test head. Automated test platforms are used in conjunction with interfaces, source and measure units, handlers or probers. The interface or connection system to provides electrical paths to the device under test (DUT) for stimuli (input) signals and measurement (output) signals. Source units provide a source signal or stimuli input. Measurement units measure the output signal from the component or DUT.