Technical information

188
230V FX Series Positioning Drive Reference Manual
Optically Isolated
A system or circuit that transmits signals with no direct electrical connection. Used to protectively isolate
electrically noisy machine signals from low level control logic.
Oscillation
An effect that varies periodically between two values. Usually refers to a variation frequency of 5 Hz or
higher.
Overshoot
The amount that the parameter being controlled exceeds the desired value.
Parallel
Refers to a data communication format wherein many signal lines are used to communicate more than one
piece of data at the same time.
Parallel Data
All the bits are available simultaneously.
Phase Angle
The angle at which the steady state input signal to a system leads the output signal.
Phase-Locked Servo System
A hybrid control system in which the output of a digital tachometer is compared to a reference square wave
signal to generate a system error signal proportional to both shaft velocity and position errors.
PID
Proportional-Integral-Derivative. An acronym that describes the compensation structure that can be used in
a closed-loop system. (see Loop, PID.)
PLC
Programmable Logic Controller. Also known as a programmable controller, these devices are used for
machine control and sequencing.
PMDC Motor
A motor consisting of a permanent magnet stator and a wound iron-core rotor. These are brush type motors
and are operated by application of DC current.
Point to Point Move
A multi-axis move from one point to another where each axis is controlled independently. (No coordination
between axes is required.)
Pole Pair, Electromechanical
The number of cycles of magnetic flux in the air gap of a rotary electromechanical device.
Position Error
The difference between the present actuator (feedback) value and the desired position command for a
position loop. Normally refers to a stationary position.
Position Feedback
Present actuator position as measured by a position transducer.