Cyber Sciences, Inc. has added precision time protocol (PTP) to its CyTime™ Sequence of Events Recorders SER-3200 and SER-2408. PTP (defined in IEEE Std 1588TM) enables sub-millisecond time synchronization over an Ethernet network. The breakthrough technology is the “hardware-assisted” time-stamping by the special 1588-compliant Ethernet hardware in the SER devices. Cyber Sciences also introduces the “Simple PTP” Profile (SPTP), based on IEEE 1588 Default Profile, which leverages the same Ethernet network used for power monitoring. One CyTime SER serves as “PTP grandmaster clock,” and all other CyTime SERs (and other PTP devices) sync automatically.
In commercial/industrial electrical networks, multiple state changes can occur within a quarter-cycle or less. One-millisecond (1-ms) resolution is the commonly accepted benchmark for meaningful analysis. Like an airliner’s black box recorder, sequence of events recorders (SERs) record exactly what happened and when, to 1 ms. Unlike the airliner example, SER data is used again and again: for root-cause analysis, advance warning of slow breakers, or to verify proper operation of automatic controls and time-current coordination. Until recently, separate cables for IRIG-B or other time-sync protocols were needed, limiting the benefits to only the largest projects. Today, PTP makes hi-res time-sync over Ethernet simple and affordable, with a solution that is scalable from small systems to the very largest sites.