Name: The Foundation of Iron — Week 5 — PLCs and Integrating Project
Author: Amine RAITI

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THE FOUNDATION OF IRON · COURSE MATERIAL · WEEK 5

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PROGRAMMABLE LOGIC CONTROLLERS
AND INTEGRATING PROJECT
Week 5 of 26 · Block 2 — Physical Automation
8h theory · 27h practice

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◆ WEEKLY LEARNING OBJECTIVES

1. Understand the logic of industrial programmable logic controllers (PLCs)
2. Translate an automation specification into program logic
3. Combine several sensors and several actuators in a single system
4. Design, build and document a complete mini automation project
5. Present and defend a technical solution in front of a group

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NOTE FOR THE INSTRUCTOR

This week is designed as a synthesis of Block 2. Exercise 2 (the integrating project) should take up most of the available time and can be individualised per pair to maintain motivation.

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Amine RAITI · Infrastructure Architect & SRE
Public document · CC BY-NC-SA 4.0 · AI Powered by Amine
Opération Dindon

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COURSE OUTLINE · 8H

THEORY GUIDING THREAD

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5.1 · Logic of industrial PLCs3h

— Difference between Arduino (prototyping) and an industrial PLC (production, robustness)
— PLC operating cycle: reading inputs → processing → writing outputs, in a loop
— Concept of Grafcet (graphical representation of a sequential automation) — conceptual introduction

5.2 · From specification to program logic3h

— Method: list inputs (sensors), outputs (actuators), transition conditions
— Direct link with the Week 3 methodology (variables → truth table → simplification)
— Importance of writing the specification before any wiring or code

5.3 · Presenting this week's integrating project2h

— Project brief: an alert or access-control system combining at least 2 sensors and 2 actuators
— Assessment criteria: compliance with the brief, wiring quality, code clarity, documentation, oral presentation

EXAMPLE BRIEF TO PRESENT

"Simplified access control system: a button acting as a keypad triggers an opening (green LED + servo motor simulating a door) if a correct sequence is entered within 5 seconds, otherwise a red LED and a buzzer signal failure."

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EXERCISE 1 · DESIGNING THE INTEGRATING PROJECT · 8H

Provided brief: each pair receives (or chooses from 3 proposals) a mini automation project combining at least 2 sensors and 2 actuators from those used in Week 4 (button, photoresistor, LED, relay, motor), with the option of adding a servo motor or buzzer provided for this week.

(1h30) Choosing or being assigned the project, reading and clarifying the brief with the instructor.

(2h) Formal specification: list of inputs, outputs, and transition conditions (method covered in 5.2).

(2h) Complete wiring diagram to draw before any physical build.

(2h) Writing the program skeleton (function structure, variables, without the full logic detail) to be validated by the instructor before Exercise 2.

(30 min) Group validation: each pair briefly presents its specification, quick feedback from the instructor.

SOLUTION — EXERCISE 1

Specification validation checklist: the list of inputs/outputs must be complete and unambiguous (each sensor and actuator has a clearly defined role), the transition conditions must cover all cases (including failure cases), and the wiring diagram must be consistent with the Arduino pins actually available.

Common mistake to correct: forgetting to specify behaviour on failure or timeout (for example, what happens if the keypad sequence is never completed?). This is an opportunity to recall that the Week 3 truth table must cover ALL possible combinations, not just the success case.

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EXERCISE 2 · BUILD, TESTING AND DEFENCE · 19H

Equipment: all equipment used in Week 4 (Arduino, breadboard, sensors, relay, motor) plus a servo motor and buzzer for this week, depending on the chosen project's needs.

(4h) Complete physical wiring of the system according to the diagram validated in Exercise 1.

(6h) Full program development, in tested increments (first each sensor/actuator in isolation, then progressive integration).

(4h) Systematic testing of all cases from the specification (success and failure cases), fixing identified bugs.

(3h) Writing short project documentation (final diagram, description of how it works, difficulties encountered and solutions applied).

(2h) Defence: each pair presents its working project (5-10 min), live demonstration, questions from the instructor and other trainees.

EXERCISE 2 ASSESSMENT GRID

Criterion 1 — Functional compliance (40%): does the system meet the full brief, including failure cases?

Criterion 2 — Wiring and integration quality (20%): clean build, reliable connections, no loose contact during the demonstration.

Criterion 3 — Code quality (20%): readable, commented, structured code (no unnecessary repetition, clear variable names).

Criterion 4 — Documentation and oral presentation (20%): ability to clearly explain technical choices and difficulties encountered.

◆ SUMMARY SHEET — WEEK 5 SELF-ASSESSMENT

1. I can explain a PLC's operating cycle.

2. I can translate a brief into an input/output/condition specification.

3. I can design a wiring diagram before any physical build.

4. I can integrate several sensors and actuators into a single coherent system.

5. I can test a system incrementally rather than all at once.

6. I can document a technical project clearly and concisely.

7. I can present and defend a technical solution orally.

8. I can identify and fix a malfunction on an integrated system.