User's Manual

87
◼ Absolute Packing Time When Using PTP
To use PTP as the clock source, users need to connect a PTP master device to get the absolute time.
Ifa PTP clocksource is selected, theLiDARwill nottransmit GPSData Packets, but onlyPointCloud Data Packetswith 4-byte μs timestamps and 6-byte
Date & Time fields. The sum of the μs timestamp and the Date & Time is the absolute packing time of this data packet.
NOTE
▪
The PTP master device is a third-party product and is not included with the LiDAR.
▪
The LiDAR’s clock follows the PTP master device according to the PTP protocol.
▪ The timestamps and Date & Time in Point Cloud Data Packets strictly follow the PTP time from the PTP master device. There maybe offset with the
Date & Time for certain PTP master devices. Please verify the configuration and calibration of your PTP master device in order to get precise time
information.
▪
The LiDAR works as a PTP slave device and the PTP protocol is Plug&Play. No additional setup is required.
▪ If a PTP clock source isselected but no PTP masterdevice is available, the LiDAR will count the time from an invalid past time. If a PTP clock source is
supplied and later stopped, the LiDAR will continue to count the time with an internal clock.
NOTE The calculation of laser firing time remains the same whether PTP is used or not, as detailed in Appendix II.