White Rabbit-based Timing System
White Rabbit-based Timing System
A Timing System specifically designed for Particle Accelerators.
The White Rabbit technology is an extension of Ethernet. It provides sub-nanosecond synchronization over 1Gps Ethernet networks with timing and data transfers among its different elements in a fully deterministic way. The solution is part of the White Rabbit (WR) Project which is lead by CERN and follows an “Open Hardware” strategy. Furthermore, now White-Rabbit has evolved. It has been used as reference for the new High Accuracy profile of the IEEE-1588-2019 Precision Time Protocol. This provides not only new features but also enhanced interoperability and standard interfaces for the end users.
Our timing devices are used worldwide for the most exigent scientific facilities. The Timing System is based on the paradigm of Time-Triggering Control as an alternative to other Timing systems based on Event-triggering control framework. The event-based approach was the preferred solution in the past due to the lack of dependable and deterministic time transfer technologies. Now thanks to the White-Rabbit technology, a paradigm shift is possible, making available a much more feature-rich, flexible and higher performance Timing Systems for the next generation of most advanced Particle accelerators. Our solution is able not only to distribute time but also provided RF dissemination with very low jitter, distribute programmable trigger signals or timestamp any event at the same time than any kind of Ethernet data traffic is distributed over the network without impacting on the timing features.
Image property of CERN
Subnanosecond and deterministic time transfer.
Subpicosecond phase noise frequency dissemination.
Very high scalability and large distance links support.
Data and time transfer over the same Ethernet optical fiber link.
Redundant network topologies supported for enhanced resilience against failures.
Programmable and low latency triggers with nanosecond resolution and subnanosecond precision.
From nanosecond to picosecond events timestamping
No calibration needed.
Interoperable with other timing protocols and IEEE-1588 profiles for best-in-class deployment
Friendly documentation, low level user-libraries as well as EPICS support.
Why choosing Seven Solutions Timing System?
Our Timing System is based on White-Rabbit / IEEE-1588 as the best design choice. Other solutions that bring precise timing and high synchronization already exist in the market, but most of them are limited in performance or flexibility or they use complex ad-hoc elements with poor support or availability. We believe that White Rabbit Solution is the best investment for a long term approach thanks to the following features:
- The WR devices are powered by FPGAs, therefore their hardware can be easily reprogrammed to be up to date.
- The WR protocol was conceived by CERN, one of the best scientific institutions in the domain of research, and it actively collaborates in the design of the OHWR products we manufacture. The implication of CERN consolidates the durability and the quality of the whole solution.
- All the elements in the White Rabbit Solution are designed to be as modular as possible in order to reduce the cost of maintenance and upgrade.
- It allows a hybrid network: the WR Switch can be used as a normal switch to connect directly to your PC in order to be quickly linked in the network. If you do not need the specific features of WR protocol, you do not need to use a specific network card. You can also use only the PTP features of the WR devices if you only need microsecond accuracy.
- The WR devices are compliant with the IEEE-1588-2019 High Accuracy profile. By simply firmware upgrade you can use a fully standardized device, avoiding interoperability issues and granting future upgrades.
- Seven Solutions offers a full product ecosystem, including modular devices based on the ZEN family & low-cost equipment such as LEN. Control and diagnostics devices, as LLRF and BPM, can be easily integrated in the final solution. Thanks to our engineering team and our support capabilities, we can help you to deploy and customize the network, achieving the best Timing System for your facility.
Our Timing System is based on the following main elements:
- Low jitter Master oscillator with possibility of integration with GNSS receivers for alignment to UTC(k) scales and resiliency options for high availability systems.
2. Time transfer and low jitter frequency dissemination based on White-Rabbit switches. Thanks to using Ethernet technology, the same timing network can be used for any kind of data distribution using the same White-Rabbit network. The solution is scalable to thousands of nodes and tens of kilometers distances.
3. End nodes including multiples interfaces for better interoperability.
The example shows how these elements of our Timing System can be deployed using White Rabbit solution as backbone technology to provide a shared notion of time to all the devices in the network and make it possible to develop a time-triggering control system.
As indicated in the figure, a common clock in the entire network is provided from a GNSS receiver and distributed using a data & timing network based on White-Rabbit switches. Different nodes (ZEN, SPECs, etc…) are powered with different FMC cards for triggering and/or timestamping operations. The Timing systems also distribute frequency with low jitter for ADCs and DAC devices distributed into the network. Their data can be read / write using the same timing network and standard Ethernet devices can be connected to retrieve such information for later processing and analysis. All the elements are programmed using friendly user-libraries and EPICS framework in order to configure the Timing System to generate the triggering signals or capture the timestamps events.