In this chapter

Chapter 1 of 13

  1. 1.1Existing exam equipment
  2. 1.2Gap and objective
All chapters
  1. 01Initial situation
  2. 02Objective and approach
  3. 03State of the art
  4. 04Requirements
  5. 05Solution approaches and concept decision
  6. 06System architecture
  7. 07The test rig
  8. 08The heated-tank model
  9. 09The simulation cycle
  10. 10Five test scenarios
  11. 11Result and limits
  12. 12Outlook
  13. 13Preliminary projects

Chapter 01 Motivation

Initial situation

Missing feedback from the IHK simulation boards as the starting point of the thesis

By Chapter 1 of 13 2 min read Updated: 30 September 2026

Summary

In vocational training, control programs are tested on simulation boards without any internal plant state; program errors remain without consequences there. The thesis replaces the board with a computational plant model against which the same controller works unchanged.

Before the exam, an apprentice checks their control program for a heated tank. The program lacks the interlock of the heating. On a real plant, the pressure would now rise unnoticed. The exam board, by contrast, does not react. The error only becomes visible when the examinee flips the corresponding slide switch themselves. They would thus have to re-create exactly the error they overlooked.

The core of the problem

The board has no internal state. It shows switch positions, but no plant behaviour.

Existing exam equipment

At the practice partner Mugler SE in Oberlungwitz, electronics technicians for industrial engineering and industrial electricians are trained. Programmable logic controllers (PLCs) are an integral part of the training, in the company mostly in the form of the Siemens LOGO! compact controller. In terms of exam equipment there were exactly two things: these controllers and the simulation boards of the Chamber of Industry and Commerce (IHK), connected via a 32-pin plug-in card. Around 30 of them are in use; they replicate, among others, a heated tank with mixer, an elevator, a singulation plant and a filling plant.

The plant itself exists on such a board only as a printed silhouette. Every process variable is set by hand; feedback is given exclusively by light-emitting diodes. What is missing is a process display, error feedback and a state that evolves on its own.

Assembled assembly from the IHK project before the bachelor's thesis.
Photo: simulation board from the IHK exam equipment, whose basic concept is several decades oldSource: Own photograph

Gap and objective

While practice moves toward networked plants, training works with setups whose basic principle is decades old. The thesis addresses this gap: the board is to be replaced by a computational model against which the same controller works with an unchanged program.

Objective and methodology follow in Chapter 2; whether the problem is solved is assessed in Chapter 11.