Technical information

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Glossary
Absolute Position
Position referenced to a fixed mechanical or electronic zero position.
Absolute Position Feedback
Position feedback devices that can maintain position data referenced to a given mechanical location even
with power off. Usually an absolute encoder or multi-stage resolvers.
Absolute Programming
A positioning coordinate reference wherein all positions are specified relative to a single reference, or
“home” position. This is different from incremental programming, where distances are specified relative to
the current position.
AC Adjustable-Speed Drive
All equipment required to adjust the speed or torque of AC induction (squirrel cage) electric motors by
controlling both frequency and voltage applied to the motors.
AC (Brushless) Servo Drive
A servo drive used to control synchronous (P.M.) or induction (squirrel cage) motors. Usually but not
always defines a drive with sinusoidal phase current control.
Acceleration/Deceleration
The change in velocity with respect to time. Acceleration refers to increasing velocity and deceleration
describes decreasing velocity.
Acceleration, Maximum from Stall
The angular acceleration of an unloaded motor, initially at rest, when the peak stator current Ipk is applied.
Accuracy
The difference between the expected value of a parameter and its actual value.
Actuator
A device which creates mechanical motion by converting various forms of energy to mechanical energy,
(i.e., hydraulic cylinder or electric motor).
Adaptive Control
A technique to allow the control to automatically compensate for changes in system parameters such as load
friction or inertia variations.
Ambient Temperature
The temperature of the air immediately surrounding the motor, drive or other device.
Amplifier
Electronics which convert low level command signals to high power voltages and currents. Usually
describes a controller intended to operate a servomotor.
Analog-to-Digital Converter
A device for converting a voltage level into a digital word.
230V FX Series Positioning Drive Reference
Manual