Abstract
Programmable Logic Controllers (PLCs) are the most used digital systems in the manufacturing industry, but there is little support for testing such systems. Despite the recommendations of the IEC 61131-3 standards, testing is mainly done manually or not at all. Recent successful attempts for a testing framework for PLCs include proposals close to object orientation. This work presents a test generation approach using such a testing system. Via our Advanced POU Testing (APTest) Framework written in a native IEC 61131-3 - compliant language, we demonstrate the automatic generation and execution of unit tests for existing software units. We introduce the software, discuss its features, and demonstrate its use.