Onthefly conformance testing of safety PLC code using QuickCheck In this paper, an approach based on the IOCOS testing relation to test safety PLC code using the tool QuickCheck is presented. Testing and validation of the safety PLC code is typically carried out on a physical system using checklists. These checklists are developed by engineers using system specification. However, due to the manual nature of checklist generation and execution, certain test cases can be overlooked and can lead to human accidents. The presented approach allows onthefly generation and execution of test cases, which expands the scope of testing by including test cases unconceived during checklist generation. Furthermore, it is demonstrated how errors in the safety PLC code are uncovered based on the IOCOS relation.

Implementation of state transition models in IEC 61499 and its use for recognition and selection of sequences of events and objects Efficient application of modelbased software design methodologies in industrial automation requires methods and tools for automatic code generation. Formal models can be especially useful to avoid ambiguity, to verify and evaluate performance, which ultimately will improve the quality and reliability of the project and lead to lower design costs. This paper proposes methods for implementing statetransition formal models, such as finite state and pushdown automata, as well as extended Petri nets (Anets) by means of IEC 61499 function blocks. These implementation approaches can be used in the design of industrial cyberphysical systems for monitoring, diagnostics, conformance checking, detection and selection of specified sequences of events and parameterized objects from an input stream. One of the proposed applications is illustrated using an example of an assembly process with LEGO blocks.