Electronic Design

GPS-Derived Grandmaster Clock Delivers Ultra-Precise Time And Frequency Sync

One good way to provide accurate time and frequency synchronization is to use the IEEE’s 1588 Precise Time Protocol (PTP). Particularly useful in non-deterministic networks like Ethernet, this technology offers major cost savings in time distribution since it can be deployed using hardware clocks and Ethernet local-area network (LAN) hubs, switches, and CAT5 cables. This standard also can make Carrier Ethernet practical. Now you can deploy that technology in your network with Symmetricom’s XLi IEEE 1588 PTP v2 Grandmaster clock (see the figure).

The XLi is a GPS referenced grandmaster clock and IEEE 1588 measurement and validation tool supporting PTP Version 2. It delivers ultra-precise time and frequency synchronization over Ethernet networks. Also, it features a dedicated 1588 time stamp processor. It functions as an IEEE 1588 slave with the ability to measure PTP client performance by assessing time transfer accuracy across a network as well.

Potential applications include aerospace and defense, test and measurement, and power utilities. The XLi can be used on test ranges and in space avionics, industrial automation, turbine control, sonar systems, and systems that do not require a separate time transfer distribution system. Furthermore, the XLi operates at 100BaseT line speed with deep time stamp packet buffers. It supports more than 50 slave delay requests per second.

The Xli also is ideal for measurement purposes as it can operate as a 1588 slave, making it extremely useful for network time transfer accuracy measurement involving a 1588 slave separated from the XLi Grandmaster by network elements or topology. It can be configured with two 1588 ports, operating as two independently configured grandmasters or as a grandmaster and slave. And, it supports all the features and functionality of its version 1 predecessor, along with:

  • Internal GPS receiver: synchronized with 12 channels
  • Oscillator options: providing stability and redundancy with oven-controlled crystal oscillator (OCXO), high-stability OCXO, and rubidium options
  • Software options and upgradeability: flexibility and software options for the network time server (NTP), frequency measure, and programmable pulse output are all available; upgradeable in the field; XLi v1 to v2 upgradeable at the factory
  • Time code: time-code input (IRIG A, B; NASA 36, IEEE 1344), IEEE 1344 time-code input/output, and multicode options for generating a wide range of time codes to synchronize

The optional TimeMonitor software collects and analyzes time interval data from the clock. It’s a set of comprehensive all-in-one test and measurement tools for collecting and analyzing IEEE 1588 packet-timing data as well as traditional synchronization signals. It’s ideal for ensuring IEEE 1588 network readiness. Also, it’s the first IEEE 1588 PTP test system to provide an intuitive pass/fail indication to easily verify PTP performance over packet networks. It helps network designers meet PTP packet sync performance requirements in multiple applications, including engineering, network planning, packet-timing deployment, and troubleshooting.

TimeAnalyzer test tools provide comprehensive functions to measure and analyze packet-timing as well as traditional synchronization. They enable reliable measurement of IEEE 1588 packet flows under a variety of traffic conditions for a broad range of networks with nanosecond accuracy.

The easy-to-use TimeAnalyzer graphical user interface enables users to quickly configure a test system, collect PTP data for performance analysis, and determine if the end results meet requirements for telecom applications. The portable device is designed for use in the field and in the lab. Data can be collected using a wide range of sampling rates (1 to 64 Hz), allowing optimization and validation of the PTP solution prior to full-scale network deployment.

The XLi IEEE 1588 PTP v2 Grandmaster and TimeAnalyzer are now available.

Symmetricom Inc.

TAGS: Defense
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