Improved Communication Model for an IEC 61499 Runtime Environment

For IEC 61499 distributed control application development the control engineer has to rely mainly on the Compliance Profile for Feasibility Demonstrations for the necessary communication infrastructure. This profile utilizes the TCP/UDP protocols and has some limitations in order to be easily used for industrial automation. With this article we identify these shortcomings and introduce an improved communication model for IEC 61499 control applications. The following three attempts to define communication interaction in IEC 61499 will be presented: (1) by function block type defined protocol, (2) by function block parameter defined protocol, (3) automatic connection. We show the impact of these attempts from the engineer's point of view. Also the required engineering tool features are presented. The result is a profile which enables the engineer to easily use different network protocols within IEC 61499 applications without the limitation to use only the TCP/UDP protocol. Furthermore, this paper shows the implementation of the developed communication profile. The implementation focuses on the runtime environment and shows how the implementation can be used by the engineer and by the engineering tool. The implementation takes strong attention to the re-usability of already implemented protocols. This is achieved by the usage of the "layered protocol" design pattern.