Parker EME
Setting up Compax3
192-120101 N11 C3I11T11 November 2007
223
4.4.9.8
Basics of frequency response measurement
In this chapter you can read about:
Distinction between signals and systems ........................................................................................223
Linear Systems (LTI System) ..........................................................................................................224
Mechanical system ..........................................................................................................................225
Resonance points and their causes.................................................................................................226
In the drive and control technology, the display of signals and systems in the
frequency range is often the best possibility to solve different tasks.
Distinction between signals and systems
Defined objects and their interactions that can be combined to a whole by a
plausible distinction from their environment (i.e. the complex reality) are called a
system.
Example electric motor
This consists of a multitude of different components, but the function and the
behavior of a motor can be described as a whole without describing each individual
component and their interactions separately.
If the motor is energized, it will generate a torque at the motor shaft.
Electro
Motor
Current
Strom
Torque
Drehmoment
Input
Eingangs
Signal
System
Ouput
Ausgangs
Signal
Current is therefore a signal, which causes at the input of the system motor a
change of its output signal torque.
In order to register and process such signals in the controller, they are digitized and
read in withthe so-called scanning frequency (fA). Thus the physical signal was
converted into a finite sequence of numbers, which can be processed in the
controller.
