Glossary

S curve refers to a control pattern that accelerates and decelerates a motor slowly to reduce mechanical shock. This function is more sophisticated than linear acceleration, but does not have the performance of camming.

Procedure that turns off the power delivered to the motor.

Refers to software and hardware that (1) permits the control or management of an entire packaging line and (2) automatically collects data on that line' s efficiency.

A series of steps to be executed that then causes an action in a machine.

Serial Real-time Communications Standard. An open communications protocol (adopted as IEC 1491) designed especially for motion-control networks. Defines a method for transmitting digital information over a fiber-optic cable at speeds of 2, and more recently, 4 megabits/sec.

Transmitting digital 1s and 0s in a series over a single cable, the primary method of communication used in and between packaging equipment. Parallel communications use several wires to simultaneously transmit groups of 1s and 0s.

A powered mechanism producing motion or forces at a higher level of energy than the input level, e.g., in the brakes and steering of large motor vehicles, especially where feedback is employed to make the control automatic.

A servo drive is a special electronic amplifier used to power electric servomechanisms. A servo drive monitors the feedback signal from the servomechanism and continually adjusts for deviation from expected behavior.

An automatic, closed-loop motion control system that uses feedback to control a desired output such as position, velocity, or acceleration.

A motor that together with its resolver or encoder is capable of being precisely controlled. A resolver or encoder provides constant and highly accurate feedback on the motor's exact position, speed and torque to the drive that powers it.

The time required for a parameter to stop oscillating or ringing aroundits final value and stabilize on it.

A cable that has a metallic sleeve wrapped around all of the conductors that comprise its center. The metal sleeve is then grounded to eliminate the effects of electrical noise on the signals being carried by the cable.

An encoder that outputs both digital and high resolution analog signals used in servo control in packaging machines.

A software function that turns physical outputs on and off, depending on the level of a specified input. Servomotors, resolvers or encoders usually offer the input for software limit switches.

Acronym for Serial Synchronous Interface. This is a type of multi-turn absolute encoder. The position information is sent from the encoder to the device reading the encoder as a serial string in Gray code format.

The amount of torque developed with voltage applied and shaft locked, or not rotating. Also known as locked-rotor torque.

The non-moving part of the motor. Specifically, it is the iron core with the wire winding in it that is pressed into the frame shell. The winding pattern determines the voltage constant of the motor.

The ability to resist movement induced by an applied torque. Stiffness is often specified as a torque displacement curve, indicating the amount a motor shaft will rotate upon application of a known external force when stopped.

The condition that occurs when several functions of a machine (mechanical, servo or software) follow a common control signal and are in a specific position according to this signal.