Precision Time Protocol

About: Precision Time Protocol is a research topic. Over the lifetime, 604 publications have been published within this topic receiving 6006 citations. The topic is also known as: PTP & IEEE 1588.

Timestamp Reliability of the Schenberg Gravitational Wave Detector Data Acquisition System

Abstract: The Schenberg gravitational wave (GW) detector has been under development for the past few years. A scientific run is planned for the near future. The main technique used to confirm a GW is the search for time coincident events between multiple detectors. Therefore, a reliable timestamp is essential for events found in data from each detector. In the particular case of the Schenberg detector, we are planning a low latency analysis, which requires that no data sample be lost during either data acquisition (DAQ) or transmission, and that time correction be done online. The aim is to provide reliable data where each sample carries its own timestamp information. GW event candidates are pointed out after a dedicated analysis and their time of occurrence are determined by these samples. We present here the DAQ solution developed for the Schenberg detector. It is easy to implement this solution using equipment commonly found in most laboratories. No specific equipment using precision time protocol or other protocol was needed to synchronize the sampling. In addition, no transmission time is needed to be explicitly known. The timing precision is limited only by the chosen sampling frequency, which fulfills the data analysis needs.

Network Time Synchronization of the Readout Electronics for a New Radioactive Gas Detection System

Abstract: In systems with multiple radiation detectors, time synchronization of the data collected from different detectors is essential to reconstruct multi-detector events such as scattering and coincidences. In cases where the number of detectors exceeds the readout channels in a single data acquisition electronics module, multiple modules have to be synchronized, which is traditionally accomplished by distributing clocks and triggers via dedicated connections. To eliminate this added cabling complexity in the case of a new radioactive gas detection system prototype under development at the French Atomic Energy Commission, we implemented time synchronization between multiple XIA Pixie-Net detector readout modules through the existing Ethernet network, based on the IEEE 1588 precision time protocol. The detector system is dedicated to the measurement of radioactive gases at low activity and consists of eight large silicon pixels and two NaI(Tl) detectors, instrumented with a total of three 4-channel Pixie-Net modules. Detecting NaI(Tl)/silicon coincidences will make it possible to identify each radioisotope present in the sample. To allow these identifications at low activities, the Pixie-Net modules must be synchronized to a precision well below the targeted coincidence window of 500-1000 ns. Being equipped with an Ethernet PHY compatible with IEEE 1588 and synchronous Ethernet that outputs a locally generated but system-wide synchronized clock, the Pixie-Net can operate its analog to digital converters and digital processing circuitry with that clock and match time stamps for captured data across the three modules. Depending on the network configuration and synchronization method, the implementation is capable to achieve timing precisions between 300 ns and 200 ps.

Time synchronization realizing method and clock node

Abstract: The invention relates to a time synchronization realizing method and a clock node. The method comprises the following steps: the clock node extracts an SSM (synchronization status message) best master clock according to the SSM, wherein the SSM best master clock is a best master clock for frequency synchronization; the clock node sets a precision time protocol (PTP) port status of a port according to the line of the SSM best master clock; and the clock node obtains a master clock data set and a best master clock data set for time synchronization according to the received notification message. Through the time synchronization realizing method and clock node provided by the invention, the PTP best master clock algorithm can be simplified.

Performance analysis of time synchronization precision of PTP in smart substations

Abstract: The precision time protocol (PTP) is fundamentally recommended in smart substations, which could potentially result in further weakening the power system. However, defects of domestic PTP devices restrict the spread of the application of PTP in smart substations. In this paper, the computation of the PTP offset in different clock modes from the two editions of 1588 standards is analyzed theoretically. Test platforms are built to study the timing accuracy of PTP performance under certain circumstances. Especially, a time synchronizing precision test is conducted under the network dataflow including certain messages like PTP, Generic Object Oriented Substation Event (GOOSE) and Sampled Value (SV). In terms of synchronizing precision and stability, the “PTP straight link” test shows that P2P is better than E2E, and that ETH is better than UDP. And the effect of boundary and transparent clock shows that the one-step “P2P-ETH” transparent clock will fulfill the application requirement in smart substation. The last test indicates that the network traffic which consists of such messages enlarge the jitter of PTP synchronization. And comprehensively, the one-step “P2P-ETH” transparent clock is suitable in smart substation.

An Approach of Time Measurement for Intelligent Components in Smart Substations

Abstract: As a high-precision time synchronization technology for distributed network,IEEE 1588 is very important for the construction of smart substations.Firstly,the principle of time synchronization of IEEE 1588,which gives the time synchronization process and the synchronization compensation algorithms of two link delay measurement mechanisms,is presented;then the time-related measurable contents during the synchronization of intelligent components,including the time synchronization accuracy of precision time protocol(PTP) utilizing intelligent components as master clock or slave clock,the sampling uniformity and output time of sampled value(SV) message and the response time and output time of generic object oriented substation event(GOOSE) message,are proposed;finally,the time-related parameters for the main transformer protection and monitoring intelligence component of UDT-531 are tested and analyzed.The results show that the measured time parameters of UDT-531 could basically meet the needs of IEC 61850 standard,thus the feasibility of the proposed time measurement approach is verified.