Glossary

Secondary Distribution is the transportation of goods and materials from distribution centers to retailers, other businesses and direct to consumers.

A semiconductor is a substance with conductive properties which can be altered with electricity; it can be both a conductor and an insulator. Silicon performs as a semiconductor when chemically combined with other elements.

Complex electronic circuits can be built into the surface of a thin layer of silicon-based semiconductor. The continuing development of semiconductor technology is a foundation for the electronics and high-tech industry sectors.

Sequence Control is the control of a series of machine movements, with the completion of one movement initiating the next. The extent of movements is typically not specified by numerical input data. It could also be refer to control of the logic of machine operations, such as the start-up sequence of a complex machine, which may require lubrication and cooling systems to be running before a main motor is started.

A servomechanism includes a controller which drives a motor to move a mechanism so that the position, speed or some other characteristic of the mechanism matches an input signal. The distinctive feature of a servomechanism is that it uses feedback from the mechanism, so it is classified as a closed loop control.

A servomotor is the electrical motor used in a servomechanism. Control inputs such as rotation speed and angular position are typical.

Commonly confused with sewerage, sewage is waste from domestic households (and in some areas industry and commerce) that is carried away by a network of pipes.

Commonly confused with sewage, sewerage is the network of pipes used to transport sewage away from its source. Also known as the waste-water system.