Module Overview

Programmable Logic Controllers

To equip students with the knowledge and skills required to design, implement and fault find basic PLC controlled industrial applications.

Module Code

PIAA H2014

ECTS Credits


*Curricular information is subject to change

PLC Architecture

Functions of input interface, output interface, CPU, Power Supply. PLC memory, programme, and PLC scan cycle. Source and sink inputs. Safety aspects of PLC control and machine interlocks.

Field Devices

Input devices including: push buttons, trip rollers, reed switches, inductive sensors, capacitive sensors, photo sensors. Output devices including: relays, contactors, motors, solenoids. Normally open, normally closed switch operation. PNP and NPN transistor sensors and their connection to PLCs.

PLC Programming

Logic operations AND, OR, NOT; Truth tables and ladder diagram implementation. AND-OR blocks. Internal relays, pulse relays, latching relays. Counters and timers. PLC programming using ladder and instruction list formats. IEC 1131-3 programming languages standard. Data registers and data manipulation. Sequencing and step ladder programming. Hand-held programmers and PLC programming software.

PLC Projects

PLC wiring projects: wiring of various sensors, NPN and PNP type sensors, sink/source connections, N/O and N/C contacts. wiring of various actuators: wiring of various actuators, contactors, relays, lamps, buzzers. Safety: e-stops, safety relays. Programming: design and implementation of basic programs to meet given specifications. Project documentation I/O schedules and wiring diagrams, fully commented program.

Module Content & Assessment
Assessment Breakdown %
Other Assessment(s)100