Controlling concurrent events in IEC 61499 based systems on FPGAs

IEC 61499 is currently explored at a rapid pace, although only few studies were conducted on the role of FPGAs for automation systems based on IEC 61499. With the necessary time quantization for synchronous FPGA systems, a new problem arises – the phenomenon of simultaneous events. Additionally, fan-ins of events complicate the requirements for the system, as it must be ensured that all arriving events are considered. This work proposes an implementation for concurrent events for FPGAs in the context of IEC 61499. To overcome the described problem, the incoming events are split into several single bit signals and are stored in a ring buffer. The proposed approach is verified in simulations of typical situations, testing the behavior of the system with respect to simultaneous events.