Towards IEC62439-3: Implementing Linux based (ZHAW-InES) PRP stack with non-PRP passthrough on ethernet networks in QNX

摘要

This paper discusses the techniques necessary to implement the InES Linux based IEC 62439-3 (PRP) protocol as a software module within the QNX networking driver environment, which also supports non-PRP traffic simultaneously. Comparisons to other implementations of the PRP stack are discussed. We leverage the NetBSD-based network stack implementation of QNX, and discuss common API calls which are suitable to implement a dual-mode PRP driver for QNX. The software behavior for ingress, egress, and management traffic specific to PRP is discussed at the API level. We show the CPU utilization performance of the PRP network as compared to non-PRP networks, along with QNX microkernel specific concerns. Caveats to this approach and mitigations are discussed.