Serial port may require USB-to-serial converters to allow compatibility with RS-232 serial devices. Serial ports are still used in applications such as industrial automation systems, scientific instruments, point of sale systems and some industrial and consumer products. Server computers may use a serial port as a control console for diagnostics. Network equipment (such as routers and switches) often use serial console for configuration. Serial ports are still used in these areas as they are simple, cheap and their console functions are highly standardized and widespread. A serial port requires very little supporting software from the host system. Some computers, such as the
Parallel and counter parallel Parallel and counter parallel In music, a parallel chord (relative chord, German: "Parallelklang") is an auxiliary chord derived from one of the primary triads and sharing its function: subdominant parallel, dominant parallel, and tonic parallel. The term is derived from German theory and the writings of Hugo Riemann (see: Riemannian theory). For example, the major and and minor and . The parallel chord (but "not" the counter parallel chord) of a major chord will always be the minor chord whose root is a minor third "down" from the major chord's root, inversely the parallel chord of a minor chord will