Introduction to IEEE 1588 and Transparent Clocks
In measurement and control systems there is often a need to synchronize distributed clocks. Traditionally, synchronization has been achieved using a dedicated medium to convey time information, typically using the IRIG-B serial protocol. The Precision Time Protocol (standardized by IEEE 1588) has been designed as an improvement to current methods of synchronization within a distributed network of devices. PTP is a message based protocol that can be implemented across packet based networks including, but not limited to, Ethernet. Standard Ethernet switches introduce a variable delay to packets that inhibits path delay measurements. Transparent clocks (enhanced Ethernet switches) have been introduced to measure and adjust for packet delay, thus removing the negative effects that these variations cause.