RoboSense Ruby Plus User Manual page 17

<4> Latitude hemisphere N (Northern Hemisphere) or S (Southern Hemisphere)
<5> Longitude
<6> Longitude hemisphere E (Eastern Hemisphere) or W (Western Hemisphere)
<7> Ground speed
<8> Ground course
<9> UTC date
<10> Magnetic declination
<11> Magnetic declination direction: E (East) or W (West)
<12> Mode indication (A = Autonomous positioning, D = Differential, E = Estimated,
N = Data invalid)
*hh at the end represents the XOR sum of characters from $ to *
Note:
1)
The GPS_REC interface specification on the Ruby Plus power box is JST
S12B-J11DK-TXR, with pin definitions shown in Table 8.
2)
The interval for sending 1 PPS pulse should be controlled within 1s ± 200 us.
3)
Time synchronization through GPS_REC is only allowed when the positioning status
in the GPRMC message is valid (A).
4)
Ruby Plus is compatible with most GPRMC message formats from GPS modules
available in the market. If any compatibility issues are found during use, please
contact RoboSense.
2.5.5.3 PTP Synchronization Principle
PTP (Precision Time Protocol, IEEE 1588V2 protocol) is a time synchronization
protocol used for high-precision time synchronization between devices. It can also be
used for frequency synchronization between devices. Compared to various existing
time synchronization mechanisms, PTP offers the following advantages:
1) Compared to NTP (Network Time Protocol), PTP can meet higher precision time
synchronization requirements. NTP generally achieves sub-millisecond level time
synchronization accuracy, while PTP can reach sub-microsecond level accuracy.
2) Compared to GPS (Global Positioning System), PTP has lower construction and
maintenance costs.
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Ruby Plus User Guide