BIA205S

Unit Description and General Aims

The objective of this unit is to impart to the students: the ability to interpret electrical control schemes and their digital equivalent schemes; and, to design such schemes to achieve a given set of control objectives. Students will also be given sufficient instruction for them to have a thorough knowledge of the internals of a PLC, and the ability to create simple programs to achieve a given set of requirements. Students will complete a project covering the design of a control scheme, program the same on a PLC (simulation), and test the operation of this program.

Learning Outcomes

On successful completion of this Unit, students are expected to be able to:

1. Use PSIM software (or equivalent) to draw simple circuits
   Bloom’s Level 6
2. Create logic diagrams to achieve specific control functionalities.
   Bloom’s Level 6
3. Translate the logic diagram to create hardwired control schemes (ladder type).
   Bloom’s Level 4
4. Design control systems of feedback/feed-forward type of control and evaluate their stability.
   Bloom’s Level 6
5. Explain the fundamental principles behind programmable logic controllers (PLC).
   Bloom’s Level 4
6. Distinguish between different methods of programming PLCs based on IEC 61131-3.
   Bloom’s Level 4
7. Create and test a PLC program to achieve specific control functionalities.
   Bloom’s Level 6

Student assessment

Prescribed and Recommended Readings

Textbooks

• IDC Technologies Course manual on PLC programming
• IDC Technologies course manual on Control loop tuning

Notes and Reference Texts

• Phipps, CA, 1999, Fundamentals of Electrical Control, 2nd Edition, Fairmont Press, ISBN 978-0130126993

• IDC Technologies, Practical Programmable Logic Controllers (PLCs) for Automation and Process Control, IDC Technologies, Perth.
• Hackworth JR, Hackworth FD, Programmable Logic Controllers: Programming Methods and Applications. Online version available at http://www.nfiautomation.org/FREE_Download/Technical%20Documents/PLC/%28eBook%29%20%20PLC%20Programming%20Methods.pdf
• References from authentic websites on the Internet:

For example:
http://www.plcdev.com/a_quick_tutorial_on_rslogix_emulator_5000 : A Quick Tutorial on RSLogix Emulator 5000.

Unit Content

Topic 1

PSIM

1. Software introduction
2. Circuit design
3. Circuit drawing in PSIM
4. Simulation and analysis

Topics 2, 3 and 4

Control scheme interpretation and design

1. Need for control schemes
2. Symbols used in control circuits
3. Motor controls – unidirectional
4. Motor control – reversing
5. Interlocks for control/safety
6. Interpreting the operation of a control circuit
7. Design a control circuit in the form of a logic diagram for a given set of requirements and evaluation using Boolean algebra principles
8. Translating a logic diagram into a control circuit
9. Control systems (Open and closed loop), transfer function and block diagrams
10. Feedback controls and feed forward controls
11. Proportional, integral and derivative (PID) control
12. Analog and digital control
13. System stability criteria and loop tuning

Topics 5 and 6

Digital logic circuits and integrated circuits for logic applications

1. Fundamentals of digital electronics
2. Introduction to Logic gates
3. Diode-resistor logic (DRL)
4. Emitter coupled logic (ECL)
5. Resistor-transistor logic (RTL)
6. Diode transistor logic (DTL)
7. Transistor to transistor logic (TTL)
8. Positive and negative logic
9. Typical circuits for logic functions
10. Logic gates using integrated circuits
11. Other useful functions such as timers, counters, flip-flop (two-state) devices and etc. using ICs
12. Introduction to clocked (dynamic) digital logic circuits

Topics 7 and 8

Programmable logic controller basics

1. Historical overview
2. Clocked logic as the basis of programmable logic controllers
3. Fundamentals of PLC hardware
4. Block diagram of a PLC
5. PLC processor module
6. Internal memory and its organisation
7. Input-output section
8. Power supplies
9. Noise control from I/O connections
10. Recommended precautions in wiring
11. Operation of dynamic logic by step-by-step execution
12. Comparison of hard-wired logics with PLCs
13. Possible concerns in using PLC (focus on safety systems)

Topics 9 and 10

Programming methods based on IEC standard 61131-3

1. PLC programming basics
2. The need for a programming standard
3. Ladder logic programming
4. Structured text method
5. Function block method
6. Instruction list
7. Sequential function chart
8. Comparison between IEC61131-3 and C programming
9. Good programming habits
10. Code organisation and documentation
11. Maintenance of program code and change documentation
12. Simple examples of programming
13. Communication between PLCs

Topic 11

Program creation and testing

1. Demonstration of program writing using RSLogix 5000 emulator (or any other simulator)
2. Use of chassis monitor
3. Step-by-step development
4. Demonstration of the program using the simulator
5. Testing/troubleshooting

Topic 12

Unit Review

In the final week students will have an opportunity to review the contents covered so far. Opportunity will be provided for a review of student work and to clarify any outstanding issues. Instructors/facilitators may choose to cover a specialized topic if applicable to that cohort.

Software/Hardware Used

Software

• Software: PSIM

• Version: N/A

• Instructions:  N/A

• Additional resources or files: N/A

Hardware

• N/A