This document introduces flow charts and timing diagrams as essential tools for programming PLC applications. It outlines the process of problem-solving, emphasizing the creation and conversion of flowcharts to ladder diagrams, as well as methodical approaches to defining and analyzing control problems. The document also details the construction of flowcharts through understanding processes, sequencing operations, and utilizing decision blocks for branching.

1. Unit 2
Flow Chart and Diagram

2. Introduction
 Flow chart and timing diagram are the
most basic things that students must be
able to know
 It shows the basic instruction for PLC
applications before start programming
using ladder diagram

3. Learning Outcome
 After completing this topic, student should
be able to:
Describe a problem and their solution in
structured way
Create flowchart to represent problem and
the solution
Convert flowchart method to ladder
diagram programming method

4. Sequential and Process Problem
Problem solving method, a good problem
should answer this questions:
What is the control problem??
Who has the control problem??
What form the solution can be??
 5 questions: what, how, where, when, and
why

5. Problem Understanding and Action
 Problem definition
 Problem analysis
 Generating possible solutions
 Analyzing the solutions
 Selecting the best solutions
 Planning the next course of action (next
step)

6. Introduction to Flowchart
 Flow charts are easy-to-understand
diagrams showing how steps in a process
fit together.
 This makes them useful tools for
communicating how processes work
 Furthermore, the act of mapping a
process out in flow chart format helps to
clarify your understanding of the process

7. Introduction to Flowchart cont.

8. Introduction to Flowchart cont.
 Water Level Warning System Process,
Water level
danger
Start
Read water
level sensor
OFF
alarm
ON alarm
Finish
yes
no

9. Flowchart and Process
A flowchart
of Tank Filter
System

10. Flowchart and Process cont.
 The general method for constructing
flowcharts is:
 Understand the process.
 Determine the major actions, these are drawn
as blocks.
 Determine the sequences of operations, these
are drawn with arrows.
 When the sequence may change use decision
blocks for branching.

11. Flowchart to Block Logic and
Ladder Diagram
Add labels
to each
block in the
flowchart

12. Flowchart to Block Logic and
Ladder Diagram cont.
Label the
Flowchart
Blocks and
Arrows

13. Flowchart to Block Logic and
Ladder Diagram cont.
The
transition
logic

14. The function
logic and
outputs