A Frame Packing Framework for Control Systems

Abstract: Ethernet has become more and more popular in the industrial world. The full duplex standard and the arrival of switches have made this protocol competitive for real-time purposes. In automation systems, a lot of energy is invested to integrate technologies using Ethernet into control systems. Since Ethernet frames have an important payload, and control signals a very small size, monopolizing an Ethernet frame for a single signal is quite inefficient. A solution to reduce this overhead is to allow sending several signals into the same Ethernet frame. This problem, close to the bin packing problem, is NP-hard. With signals having end-to-end deadlines to respect and different periods and release times, this problem becomes even more complex. We propose here to design a communication framework realizing such a frame packing. The challenge is to generate near-optimal solutions in terms of bandwidth utilization while meeting the different real-time constraints related to automation control systems.