White Rabbit Calibration
Relative calibration
-
White Rabbit devices
calibration
- provides coarse calibration values for the official releases of WR Switch and WR PTP Core firmware. You can use them as defaults for matching hardware and gateware version. However, to achieve the best possible synchronization results you should perform the full calibration procedure for your WR hardware.
- WR Calibration Procedure
Absolute calibration
Absolute calibration is achieved by measuring the time relationship (Δ TXcal, Δ RXcal) between the external electrical phase planes of the PPS signal and the interface to the Electrical-Optical / Optical-Electrical converter (EO/OE, usually the electrical SFP connector) as shown in Figure 1. Note that EO/OE converters have their own calibration parameters that define the relationship between their electrical and optical phase planes. Calibration of EO/OE converters is not covered on this wiki page.
Figure1: White Rabbit link delay model for absolute calibration*
Absolute calibration enables independent developers and/or vendors to
exchange their WR gear while achieving sub ns timing synchronisation.
Absolute calibrated devices can be used as "golden standards" for the
relative calibration
procedure.
-
WR calibration - ASTERICS -
Nikhef
- Aims to provide a method of absolute calibration of all elements of a WR device (preliminary).
For absolute calibration special hardware is needed:
19 May 2016