Glossary

CANopen is a communication protocol and device profile specification for embedded systems used in automation.

Centralized control is a control system in which all of the primary processing is done at a single location rather than at multiple points throughout the system.

Circular interpolation is the generation of an apparently circular motion through the coordinated movements of two axes. The actual path is a series of straight line approximations generated by software algorithms.

Closed Loop is a broadly applied term, relating to any system in which the output is measured and compared to the input. The output is then adjusted to reach the desired condition. In motion control, the term typically describes a system utilizing a velocity and/or position transducer to generate correction signals in relation to desired parameters.

Clogging is a term used to describe non-uniform angular velocity. Cogging appears as a jerkiness, especially at low speeds.

Collision detection is the use of sensors to detect the imminent impact of two or more parts in a system. The signals from the detection sensors can be used to stop motion or to provide a ramped slow down for a “soft” mating of the approaching components.

Commutation is a term which refers to the action of steering currents or voltages to the proper motor phases so as to produce optimum motor torque. In brush type motors, commutation is done electromechanically via the brushes and commutator. In brushless motors, commutation is done by the switching electronics using rotor position information obtained by Hall sensors, a tachometer, or resolver.

Controller is a term describing a functional block containing an amplifier, power supplies, and possibly position-control electronics for operating a servo motor or step motor.

Converter is the process of changing AC to DC and back to AC again. This is accomplished through the use of a diode rectifier or thyristor rectifier circuit. The term "converter" may also refer to the process in an adjustable frequency drive, consisting of a rectifier, a DC intermediate circuit, an inverter and a control unit.

Coordination is the integration of the movements of two or more axes of motion so that the resultant motion is a path which none of the axes are capable of independently. Coordination may also involve the use of sensors and other internal or external commands in the integration effort which assist in effecting the movement or work desired.

Current at Peak Torque is the amount of input current required to develop "peak torque". This is often outside the linear torque/current relationship.

Current controller is a  system that utilizes an electronic method of limiting the maximum current available to a motor. This current is adjustable so that the motor’s maximum current can be controlled and normally includes functions that serve as a protective measure to prevent extended overload conditions from damaging the motor or the controller.

Current - rated is the maximum allowable continuous current a motor can handle without exceeding motor temperature limits.

Cut to length is a sub-routine within a motion control processor or stand-alone processor that is designed to feed material being processed a pre-set distance prior to performance of a secondary function such as a cut off. Feedback systems are employed to ensure repeatability of the set feed length.