As a software-only implementation of the IEEE 1588 Precision Time Protocol (PTP), a new protocol stack from Real-Time Systems GmbH (RTS) eliminates the need for hardware-based time stamping and delivers accuracies of up to ±5 µs or better. Formerly, implementations of the IEEE 1588 protocol requiring high accuracy also needed hardware time stamping, which added non-standard components and increased costs. The RTS stack uses only common network interfaces. The software particularly suits use in instrumentation, automation systems, and process-control networks.
The RTS IEEE 1588 Software Protocol Stack includes all servo algorithms, regulators, filters, a PTP-Clock based on a hardware timer, and direct Timer access. The software is fully tested and comes with documentation and an example implementation on VxWorks for x86. The stack is available with source code to qualified customers. The PTP automatically synchronizes multiple devices with the most accurate clock found in a packet-based network—typically Ethernet. The RTS protocol stack automatically determines the most accurate clock, known as the Grand Master Clock. During operation and after initial synchronization, the PTP real-time clocks are constantly adjusted by exchanging timing messages. The stack uses statistical techniques to further reduce residual fluctuations. Because the RTS IEEE 1588 protocol stack supports the PTP hot-pluggable functionality requirement, devices may join or leave the network at any time.