Response time for IEC 61499 over Ethernet

The IEC 61499 standard provides means to specify distributed control systems in terms of function blocks. The execution model is event driven (asynchronous), where triggering events may be associated with data (and seen as a message). In this paper we propose a low complexity implementation technique allowing to assess end-to-end response time of event chains spanning over a set of networked devices. In this paper we develop a method to provide safe end-to-end response time taking both intra- and inter-device delivery delays into account. As a use case we study the implementation onto (single-core) ARM-cortex based devices communicating over a switched Ethernet network. For the analysis we define a generic switch model and an experimental setup allowing us to study the impact of network topology as well as 802.1Q quality of service in a mixed critical setting. Our results indicate that safe sub millisecond end-to-end response times can be obtained using the proposed approach.