Programming of industrial controllers

Industrial controllers are an inseparable element of automation and control systems for all types of machinery, equipment and industrial processes.

The author, using the experience gathered during the years of conducting didactic classes and specialist courses, presented a uniform, coherent and transparent concept of programming PLC controllers, based on the recommendations and definitions introduced in the IEC 61131 standard. In an accessible and exhaustive way, he discussed:

• basics of construction and operation as well as equipment of PLC controllers;
• data types and variable declaration;
• organizational units of the software;
• programming languages (IL, ST) and graphic (LD, FBD);
• sequential functional diagrams (SFCs);
• functions and standard functional blocks;
• declaration of configuration;
• modern programming tools, including Concept package.

He has put together many practical examples of PLC programming. The substantive value of the book is increased by the additions, containing definitions of selected terms in the field of controllers in accordance with IEC 61131 and a dictionary of more important English terms.

The book is intended for students of automation and robotics as well as engineers and technicians interested in the use of PLC controllers. It can be both an academic textbook and a tutorial for programmers.


Table of Contents

Preface

Chapter 1
Admission
1.1. Historical view
1.2. IEC 61131 standard
1.2.1. The goals and advantages of the norm
1.2.2. Components of the standard.
1.3. Functional characteristics of the controller
1.3.1. Signal processing functions
1.3.2. Interface functions with sensors and actuators.
1.3.3. Features of the human-machine interface
1.3.4. Communication and power functions
1.4. Book layout

CHAPTER 2
Introduction to PLC programming
2.1. Construction and operation of the controller
2.2. Basics of programming controllers
2.2.1. Electromechanical relay
2.2.2. Example of a relay motor control system
2.2.3. Motor control by means of a PLC controller
2.2.4. Motor control with delayed switching
2.2.5. RS and SR flip-flops

CHAPTER 3
PLC equipment
3.1. Controller architecture
3.1.1. Driver modules
3.1.2. Controller configuration
3.2. CPU Central Unit
3.2.1. Program cycle and work modes
3.2.2. Configuration of the central unit
3.3. Digital input modules
3.4. Digital output modules
3.5. Analog input modules
3.5.1. Analog input module for current signal
3.5.2. Analog input module for voltage signal
3.5.3. Temperature measurement systems
3.6. Analog output modules
3.7. Communication in PLC systems
3.7.1. Standard serial links
3.7.2. Local networks
3.7.3. Communication protocol
3.7.4. Industrial networks
3.8. Systems with redundancy
3.9. PLC family of various manufacturers

CHAPTER 4
Programming of controllers in accordance with IEC 61131-3
4.1. IEC 61131-3 standard
4.1.1. Software model
4.1.2. Communication model
4.1.3. Advantages of using the IEC 61131-3 standard
4.2. Principles of software development
4.2.1. Program structure
4.2.2. Declaration of variables
4.2.3. Software unit code
4.2.4. Assignment of the controller
4.3. Common elements of languages

CHAPTER 5
Data types and variables
5.1. Ways of presenting data (literals)
5.2. Meaning of variables and data types
5.3. Data types
5.3.1. Elementary data types
5.3.2. Derived data types
5.3.3. Declaration of initial values for the data type
5.4. Variables
5.4.1. Simple variables
5.4.2. Multi-element variables
5.4.3. Initial values of variables
5.4.4. Variable attributes
5.4.5. Declaration of variables in a graphical manner

CHAPTER 6
The organizational units of the software
6.1. Functions
6.1.1. Control of execution in graphic languages
6.1.2. Declaration of functions
6.2. Functional blocks
6.2.1. Creating a copy of FB
6.2.2. Declaration of a functional block
6.3. programs
6.4. Calling functions and function blocks

CHAPTER 7
Programming languages
7.1. IŁ language (List of orders)
7.1.1. IŁ language operators
7.1.2. Calling funks and function blocks
7.1.3. Other elements of the language IŁ
7.2. ST Language (Structured Text)
7.2.1. expressions
7.2.2. Instructions
7.3. LD language (ladder diagram)
7.3.1. Circuits and execution control
7.3.2. Contacts and coils
7.3.3. Calling functions and function blocks
7.3.4. Principles of creating circuits
7.4. FBD language (Functional flowchart)
7.5. Language compatibility
7.6. Sample tasks
7.6.1. Start-stop system
7.6.2. Switching off with delay
7.6.3. Square wave generator
7.6.4. Two-position regulation with hysteresis

CHAPTER 8
Structuring the program using SFC
8.1. Synthesis methods of the control algorithm
8.1.1. State table
8.1.2. State graph
8.1.3. Ladder diagram
8.1.4. Grafcet
8.2. Sequential functional diagram SFC
8.2.1. Steps
8.2.2. transitions
8.2.3. Steps and transitions sequences
8.2.4. Actions and blocks of shares
8.2.5. Associating steps with actions
8.2.6. Share qualifiers
8.2.7. Control of execution
8.2.8. Summary of SFC properties
8.3. Examples of using SFC
8.3.1. Controlling the filling of tanks
8.3.2. Synchronization of two SFC networks

CHAPTER 9
Functional and standard functional blocks
9.1. Standard functions
9.1.1. Typing
9.1.2. Type conversion functions
9.1.3. Numeric functions
9.1.4. Functions on bit strings
9.1.5. Selection and comparison functions
9.1.6. Functions on strings
9.1.7. Functions on data types related to time
9.1.8. Functions on enumerated data types
9.2. Standard functional blocks
9.2.1. Two-state elements
9.2.2. Elements of slope detection
9.2.3. Counters
9.2.4. timers

CHAPTER 10
Declaration of configuration
10.1. Configuration items
10.1.1. configurations
10.1.2. Resources
10.1.3. Works
10.1.4. Associating tasks with the organizational units of the software
10.1.5. Access paths
10.2. Configuration example
10.2.1. POU declarations in the example
10.2.2. Declaration of configura in the example
10.2.3. Control of execution

CHAPTER 11
Modern programming tools
11.1. Basic functions
11.1.1. Project management
11.1.2. Editing the program's source text
11.1.3. Compilation
11.1.4. Configure the equipment
11.1.5. Communication with the controller
11.1.6. Remote control of the controller
11.2. Testing and running the program
11.3. Project documentation

CHAPTER 12
Concept package
12.1. General information
12.2. Concept package support
12.2.1. Open an existing one or create a new project
12.2.2. Controller configuration
12.2.3. Declaration of variables
12.2.4. Sections of the program
12.2.5. Editing program sections
12.2.6. Entering library elements into the program
12.2.7. ONLINE functions
12.2.8. Import and export of design fragments
12.3. Functional derivative blocks (DFB)
12.4. SymulatorIEC
12.5. Examples of programs
12.5.1. Description of the task
12.5.2. Declaration of variables
12.5.3. Program in FBD language
12.5.4. Program in the LD language
12.5.5. Program in IŁ language
12.5.6. Program in ST language

Literature
Definitions of selected terms in accordance with IEC 61131
Dictionary of major English terms and abbreviations
Index