Determinism and Time-Sensitive Ethernet (TSN)

Standard Ethernet is not real-time-enabled because it is not deterministic. The lack of determinism is due to the fact that while information collisions are indeed flagged in traditional CSMA/CD processes, they are not avoided however. This results in considerable time fluctuations when transmitting information. Admittedly, collisions are avoided in switched Ethernet due to full duplex transmission and point-to-point connections. However, additional lag times and nondeterministic delays during high-peak periods have been recorded when using switches.

IEEE has a Time-Sensitive Networking (TSN) task force that aims to extend existing Ethernet standards to achieve a degree of determinism that meets the hard real-time requirements of modern industrial automation control networks. Specifications are still being defined. Sercos expects to be fully compatible with TSN.