Siemens Module B3 ユーザーズマニュアル

 

 

 

 

 

 

 

   

 

 

 

 

T I A  Training Document 

Page 8 of 64 

  Module 

 

 

Below, the basic terminology of control engineering is explained in detail. 

First, an overview shown in the diagram below: 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Measuring          
Device 

Controlled 
System 
 

Final 
Control 
Element 

 
Actuator

Controlling
Element 

Comparing 
Element 

      Controller 

 

It is the actual “objective“ of the control process: the variable that is to be influenced or kept constant 

is the purpose of the entire system. In our example, that would be the room temperature. The 

momentary value of the controlled variable existing at a certain time is called "actual value“ at that 

point in time.  

 

In a control loop, the controlled variable is constantly checked in order to be able to respond to 

unintended changes. The measured variable proportional to the controlled variable is called 

feedback variable.  In the example "furnace“, it would correspond to the measured circuit voltage of 

the inside thermometer. 

 

 

Preface     Fundamentals     Discontinuous Action Controller     Controller Block (S)FB41     Setting the System     Appendix 

B3 

Issued: 02/2008                                                                                                                                     Control Engineering with STEP 7