RoboSense LiDAR RS-Bpearl, User Manual

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RS-Bpearl User manual
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<6> Longitudinal hemisphere E (east longitude) or W (west longitude)
<7> Speed over the ground(knots)
<8> Track made good (degrees True)
<9> UTC date
<10> Magnetic declination
<11> Magnetic declination direction, E (east) or W (west)
<12> Mode indicator (A=autonomous, D=differential, E=estimated, N=not valid)
*The last hh is the XOR sum of all characters from $ to *
Please note that
：
1.
The sending time interval of 1 PPS pulse needs to be controlled within 1s±100us;
2.
The status bit in the GPRMC message must be A valid before time synchronization is allowed;
3. The length of GPRMC messages sent by existing GPS modules on the market is not consistent.
The length of GPRMC messages reserved in the DIFOP packet of RS-Bpearl is up to 86 bytes,
which is compatible with the GPRMC message format sent by most GPS modules on the market.
If an incompatibility occurs, please contact RoboSense technical support.
4.6.3. PTP Time Synchronization
PTP (Precision Time Protocol) is a time synchronization protocol, which itself is only used for
high-precision time synchronization between devices, but it can also be borrowed for frequency
synchronization between devices. Compared with various existing time synchronization
mechanisms, PTP has the following advantages:
1) Compared with NTP (Network Time Protocol, Network Time Protocol), PTP can meet
higher-precision time synchronization requirements. NTP can only achieve sub-second time
synchronization precision, while PTP can reach sub-microsecond time synchronization precision.
2) Compared with GPS (Global Positioning System), PTP requires lower construction and
maintenance costs.
4.6.4. PTP Wiring Diagram (Valid for RS-Bpearl 3.0)
To use the PTP synchronization method, the user need to make the following preparations,
connect devicesaccording to the connection method shown in the figure below:
1) Select PTP mode in the web interface (please refer to Appendix A.2 for Web Interface
configuration);
2) Prepare a PTP Master timing host (plug and play, no additional configuration required);
3) Ethernet switch;
4) Devices supporting PTP protocol