Function block programming for distributed control : a thesis presented in complete fulfilment of the requirements for the Master of Engineering, 216.899 thesis at Massey University, Wellington, New Zealand
This report discusses research and development using the draft IEC 61499 function block standard for distributed control with embedded microprocessor applications. This is a function block programming language that is currently under development for programming distributed control systems. The report covers what is required to develop an IEC 61499 compliant product and its suitablity for use with distributed control systems. To utilise the IEC 61499 standard, research and development of an embedded Java platform was performed. This required porting a Java virtual machine to run on an embedded microprocessor. An existing industrial network protocol DeviceNet was chosen for distributing the data between the network of control devices. To achieve this an upgrade was required to an existing DeviceNet communications engine to support distributed control. A third party IEC 61499 software application engine was ported to run on an embedded microprocessor. This option was chosen rather than completely developing a software engine as a commercial decision by the developer company. It also allowed support from other companies and researchers working with this standard. To test distributed control using this function block programming standard a test application consisting of a conveyor and three axis robot was developed. The test application demonstrated the feasibility of distributed control using IEC 61499 function blocks and some of the advantages of distributed control. Further outcomes of this research have highlighted some of the problems that require rectifying before this function block programming standard is feasible for commercial products.