User's Manual

Automation and Drives - SCE

T I A Training Document Page 33 of 64 Module

Assignment List:

Symbol: Address: Comment

Start I 1.3 Button Start

Stop I 1.4 Button Stop

AI_Level_Actual PEW 128 Analog input for the level sensor

AI_Level_Setpoint PEW 130 Analog input for the setpoint selection

AI_Level_Act_Norm MD 20 Normalized value for the level

AI_Level_Setp_Norm MD 24 Normalized value for the level setpoint

M_X1 MD 32 Intermediate flag half the differential

M_Xo MD 36 Intermediate flag high operating point

M_Xs MD 28 Intermediate flag switching hysteresis

M_Xu MD 40 Intermediate flag low operating point

Controller_On M 10.0 Flag controller is switched on

Pump A 0.0 Pump activation binary

Display_ON A 1.0 Indication: system is on

Analog FC1 Subroutine analog value processing

Two Pos.Controller FC2 Subroutine two position controller

Exercise:

Create a project with hardware configuration for a CPU314C-2 DP (refer to Module A05) and change

the addresses according to the assignment list shown above.

There, create a program in an FC1 with the following functionality:

- The analog value for the process variable Level is to be entered, and normalized to the physical

variable "Liter“. The normalized value is made available in MD20 as a floating point number.

Note: If the level is 10 liters, the level sensor returns 0V, for 100 liters 10V.

- The analog value for the setpoint is to be entered, and made available normalized as floating point

number in MD24.

Save FC1.

Then, set up the two position controller in an FC2, based on the structogram provided above.

Call FC1 for inputting the setpoint and the actual value.

Save FC2 and call it in OB1. Save OB1 and load the entire station to the PLC.

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

Issued: 02/2008 Control Engineering with STEP 7