Siemens Module B3 manual Assignment List Symbol Address Comment, Exercise

Automation and Drives - SCE

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
	T I A Training Document	Page 33 of 64		Module
				B3
Issued: 02/2008				Control Engineering with STEP 7