10_advanced functions docx

Higher Engineering Education Alliance Program
Ladder Logic
Functions
Prepared by: Ngo Van Thuyen
Topics and Objectives

Topics:

Program control: Jump function and branching and looping

Subroutines

State diagram techniques

Design examples

Objectives: After this lectures, with reference to the
programming manual students can:

Be able to use jump function appropriately

Be able to use subroutines appropriately

Be able to program with state diagram technique
Program control - JMP

Allows a parts of a ladder logic diagram to be
excluded or included in a program scan
If A is true, the program
will jump to LBL:01. If A
is false the program

goes to the next line.
Do you remember how
to write it with S7-200?
Subroutines

Why subroutines?

To divide the program into smaller tasks for easy
management

Easy for trouble shooting, program changing

Steps

Create a subroutine

Define input and output of a subroutine

Call a subroutine from a program (main program,
other subroutine or an interrupt routine)
Program control – JSR, SBR

How does
this work?
S7-200 notation
Main program
Subroutine SBR0
State diagram techniques with SBR

State diagram can be used with MCR but SBR can

be more effective
State diagram techniques (contd)

Can you explain?
Main program
State diagram techniques (contd)
State diagram techniques (contd)

Work in a group of 2 to implement the following
state diagram using subroutine