Technical information

189
Glossary
Process Control
A term used to describe the control of machine or manufacturing processes, especially in continuous
production environments.
Pulse Rate
The frequency of the step pulses applied to a motor driver. The pulse rate multiplied by the resolution of the
motor/drive combination (in steps per revolution) yields the rotational speed in revolutions per second.
PWM
Pulse width modulation. An acronym which describes a switched mode control technique used in amplifiers
and drivers to control motor voltage and current. This control technique is used in contrast to linear control
and offers the advantage of greatly improved efficiency.
Pulse Rate
The frequency of the step pulses applied. Usually used to describe the maximum pulse frequency that the
system is capable of generating or accepting.
Quadrature
Refers to signal characteristics of interfaces to positioning devices such as encoders or resolvers.
Specifically, that property of position transducers that allows them to detect direction of motion using the
phase relationship of two signal channels.
Ramping
The acceleration and deceleration of a motor. May also refer to the change in frequency of the applied step
pulse train.
Rated Torque
The torque producing capacity of a motor at a given speed. This is the maximum continuous torque the
motor can deliver to a load and is usually specified with a torque/speed curve.
Regeneration
The action during motor braking in which the motor acts as a generator and takes kinetic energy from the
load, converts it to electrical energy, and returns it to the amplifier.
Repeatability
The degree to which the positioning accuracy for a given move performed repetitively can be duplicated.
Resolution
The smallest positioning increment that can be achieved. Frequently defined as the number of steps or
feedback units required for a motor’s shaft to rotate one complete revolution.
Resolver
A position transducer utilizing magnetic coupling to measure absolute shaft position over one revolution.
Resonance
The effect of a periodic driving force that causes large amplitude increases at a particular frequency.
(Resonant frequency.)
RFI
Radio Frequency Interference.