Technical information

192
230V FX Series Positioning Drive Reference Manual
Transducer
Any device that translates a physical parameter into an electrical parameter. Tachometers and encoders are
examples of transducers.
Trapezoidal Profile
A motion profile in which the velocity vs. time profile resembles a trapezoid. Characterized by constant
acceleration, constant velocity and constant deceleration.
TTL
Transistor-Transistor Logic. Describes a common digital logic device family that is used in most modern
digital electronics. TTL signals have two distinct states that are described with a voltage - a logical “zero” or
“low” is represented by a voltage of less than 0.8 volts and a logical “one” or “high” is represented by a
voltage from 2.5 to 5 volts.
Variable Frequency Drives
An electronic device used to control the speed of a standard AC induction motor. The device controls the
speed by varying the frequency of the winding current used to drive the motor.
Vector Control
A method of obtaining near servo performance from an AC motor by controlling two components of motor
current.
Velocity
The change in position as a function of time. Velocity has both a magnitude and a direction.
Velocity Linearity
The maximum deviation between actual speed and set speed expressed as a percentage of set speed.
Voltage Constant (or Back EMF Constant or BEMF or Ke)
This is the voltage characteristic of a motor. The voltage generated by a motor as it is spun with no load.
Typically expressed as volts/Krpm.
Zero Marker
A once per revolution mark on an encoder to precisely mark a reference point from which to measure all
distance. Also generated in resolver based systems by detecting a “null” position on the resolver feedback
signals.