Verifying IEC 61499 Applications
Verification is the process of evaluating workproducts of a development phase to determine whether they meet the specified requirements for that phase. This chapter illustrates the need for verification from four well known technological incidents that would have been avoided if proper verification methods had been applied. These include: Therac-25 Radiation Overdosing; AT&T Telephone Network Outage; Pentium FDIV Bug; and Ariane 5 Disaster. The chapter addresses some techniques developed for verification of International Electrotechnical Commission (IEC) 61131 control code and describes the current achievements of IEC 61499 verification. An alternative to extensive tests of newly developed software and hardware solutions is utilization of verification methods. Tests can be assigned to analyze the following: functional, reliability, performance, operability, security, compatibility, maintainability and transferability. The chapter provides an overview of approaches designed for testing and verification of correct behavior of a running IEC 61499 application. It introduces a monitoring and debugging framework and describes adoption of a unit test for IEC 61499.