In a second test, the accuracy (absolute time error) is measured by comparing the 1PPS signal of the PTP Grandmaster with the signal generated by the PTP implementation on the HAN Pilot Platform. As the Calnex Paragon X device can only measure 1PPS signals at a resolution of 2ns, a Calnex Paragon Neo is used for this measurement to increase the resolution.

The two 1PPS signals are offset-compensated to a level of less than 2ns, accounting for different coaxial cable lengths and varying transmission delays within the respective PCS PMA units.

The results in show an the comparison from two way time error with a signal spread of less than ± 2ns exceeding the limits for the Class D performance in a network with full timing support. The results are shown in Figure 3-6. The time error when measured on the 1PPS signal shows the results are similar without any high pass filtering as shown in Figure 3-6 and Figure 3-6.

The minimum time interval error or MTIE is also very well behaved within limits, as shown in Figure 3-9

Figure 3-6 Two Way Time Error Filtered with Class D Limit Lines (±5ns), Typical Measurement

Figure 3-7 1PPS Absolute Time Error Filtered with 0.1Hz High-Pass Filter, Typical Measurement

Figure 3-8 1PPS Absolute Time Error (No Filter), Typical Measurement

Figure 3-9 MTIE Analysis, Typical Measurement