This course is designed to benefit you with practical up-to-date information on the application of PLCs for the automation and process control of plants and factories. It is suitable for people who have little or no exposure to PLCs, but expect to become involved in some or all aspects of PLC installation. It aims to give practical advice from experts in the field, to assist you to correctly plan, program and install a PLC with a shorter learning curve and more confidence. The inventible question is which PLC is being used. This course will be focusing on the generic PLC and use the open programming IEC 61131-3 standard. The information contained in this course advances from the basics to challenge even the most experienced engineer in the industry today.

YOU WILL GAIN

• An ability to specify PLC hardware and installation criteria
• Knowledge to describe PLC software structure
• Skills to write medium level PLC programs (using ladderlogic)
• An understanding of how to specify PLC systems and troubleshoot typical PLC system’s

COURSE OUTLINE

INTRODUCTION TO THE PLC

• Introduction to PLCs
• A brief history of PLCs
• Alternative control systems – where do PLCs fit in?
• Why PLCs have become so widely accepted
• Lingering concerns about PLCs

INTRODUCTION TO IEC61131-3

• Concepts
• Common elements
• Programming languages: structured text
• Function block diagrams
• Ladder diagrams
• Instruction list
• Sequential function chart

OPC

• Introduction to OPC
• What is OPC?
• Architecture

SAFETY PROGRAMMABLE FEATURES

• Why regular PLCs should not be used for safety functions
• Programmable electronic logic solvers
• Safety certification
• Certified programming systems
• Application examples
• Growth of networked safety devices and certified networks
• Integrated safety systems

FUNDAMENTALS OF PLC HARDWARE AND SOFTWARE

• Block diagram of typical PLC

USING LADDERLOGIC FOR A SIMPLE DIGITAL FUNCTION

• The basic rules
• Comparison with relay ladder diagrams
• The concept of the “scan” and how to apply it
• Infinite fan-out
• Contact “normal” states
• Positive and negative logic
• Basic Boolean functions
• The usefulness of De Morgan’s law

PLC PROCESSOR MODULE MEMORY ORGANISATION

• Input/output section – module types
• Power supplies
• Methods of representing logic
• Boolean algebra
• Instruction code
• Graphical presentation: functional logic diagrams, ladder logic
• Fundamental ladder logic instruction set
• Comparison of different manufacturers
• Memory and data representation
• Instruction code

DATA COMMUNICATION

• Interface standards, RS-232, RS-422/423, RS-485
• Protocols, Modbus and DH+
• Local area networks, Ethernet and token bus
• Monitoring communication links and simple watchdog timers

USING REGISTER (WORDS)

• Number systems
• Types of register data
• Timers
• Counters
• Bit shift/rotate
• Table functions
• Register (matrix) logic functions

GOOD PROGRAMMING HABBITS

• Keeping track of addresses and data used
• Looking ahead – how will programs be maintained
• Practical methods to improve program quality
• Organisation of code
• Through documentation
• Simplifying changes

BATCH PROCESSES AND SEQUENTIAL CONTROL

• Remembering the program state
• Creating a “stepper”
• Step advance
• Fault detection and recovery
• Operator intervention
• Multiple recipes or alternate paths
• Sequential function charts

GOOD INSTALLATION PRACTICE

• Location of hardware
• Good wiring practice
• Cable spacing
• Power distribution
• Wire numbering
• Reducing noise and interference
• Screening and shielding
• Earthing and grounding

ADVANCED CONTROL WITH PLC

• The concept of reusable logic - examples: drive logic, alarm handling
• Use of advanced programming functions
• Matrix logic
• Table functions and indirect addressing
• Examples: simple display driver

PID CONTROL

• The importance of timing and scan time
• When PID is not always appropriate:
• Intermittent measurements
• Long transport delays

SYSTEM CHECKOUT AND TESTING

• Development and verification of code
• Factory acceptance testing
• Testing procedures
• Emulating missing hardware
• Emulating process responses