1PPS Asymmetric Compensation Examples

Enhanced PTP User Guide (UG1602)

Document ID
UG1602
Release Date
2022-10-18
Revision
1.0 English
Figure 1. 1PPS Example

In the above example the initial observed 1PPS offset is -3400. This value is doubled and applied to sfptpd using the ptp_rx_latency parameter as 6800.

sfptpd is restarted and the next observed 1PPS offset is -300, this value again is doubled and applied to the original compensation value (6800 + 600 = 7400).

sfptpd is restarted and the final observed 1PPS offset is +50 meaning the previous compensation value caused sfptpd to over-compensate, so the +50 is doubled and subtracted from the previous compensation value (7400 - 100 = 7300).