Editing Automatic test equipment (section)

===Universal Serial Bus (USB)===
[[USB]] connects peripheral devices, such as keyboards and mice, to PCs. USB is a [[Plug & Play|Plug and Play]] bus that can handle up to 127 devices on one port, and has a theoretical maximum throughput of 480&nbsp;Mbit/s (high-speed USB defined by the USB 2.0 specification). Because USB ports are standard features of PCs, they are a natural evolution of conventional serial port technology. However, it is not widely used in building industrial test and measurement systems for a number of reasons; for example, USB cables are not industrial grade, are noise sensitive, can accidentally become detached, and the maximum distance between the controller and the device is 30&nbsp;m. Like [[RS-232]], USB is useful for applications in a laboratory setting that do not require a rugged bus connection.