Protocol Requirements
The protocol should enable the distribution of an arbitrary number of RF clock signals, using the IEEE1914.3 standard as follows:
- Phase alignment of the RF signal at a picosecond resolution.
- A frequency range from 1 MHz to 10 GHz.
- An update rate of frequency and phase information up to 250 kHz.
- Multiplexing of simultaneous RF signal transmission in an Ethernet network.
In addition, we also want to support the following features:
- Transmit application-specific (control) data via an Event mechanism.
- Efficient use of Ethernet network bandwidth.
- Support of a secondary presentation time called RFtime.
Requirements/results from current users
Based on the following references for respective users: CERN , ESRF, SPring-8
Parameter | CERN | ESRF | SPring-8 |
---|---|---|---|
Phase-alignment - required | 10ps | - | <50ps |
Jitter (RMS) - required | <0.25 ps | <50ps | < 10ps |
Jitter (RMS) - measured | < 0.1 fs (10 Hz-10 MHz) | ~10ps | 6ps (10 Hz-20MHz) |
Simultaneous signals | 2 | ~5 | 2 |
Frequencies distributed | 200 MHz |
352 MHz RF clock, 1 MHz & 355 KHz revolution freq. 4 Hz & 10 Hz for injection |
508.58 MHz RF clock 208.8 KHz revolution freq. |
Distributed frequency | varying | varying | varying |
RF time event distribution | yes | yes | yes |
Application (system) | Accelerating radio-frequency cavities |
Accelerator subsystems require RF signal and triggers initiating sequential actions synchronous to the RF signal, such as ”gun trigger”, ”injection trigger” or ”extraction trigger” |
Experiments require synchronization with RF of storage ring. These measurements include nuclear resonant scattering, time-of-flight, and pump and probe time-resolved measurements using laser pulses. |