Hesai QT128C2X, User Manual

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Four single-return modes and five dual-return modes are available, indicated by the Return Mode field in the Tail of Point Cloud Data Packets.
In a single-return mode, Blocks 1 and 2 use Firing Sequences 1 and 2, respectively.
Notes
· Firing sequences are defined in Appendix II (Absolute Time of Point Cloud Data).
· If a channel does not fire in the current firing sequence, its corresponding four bytes are filled with 0.
In a dual-return mode:
· the measurements from each round of firing are stored in the two blocks of one packet (see table below);
· azimuth changes every packet;
· firing sequence changes every packet, indicated by the Mode Flag field in the Tail.
Return Mode field Block 1 Block 2 Note
0x39 Last return Strongest return If the last return is also the strongest, then the even-number block stores the
second strongest return.
0x3B First return Last return If there is only one return, then the two blocks store the same data.
0x3C First return Strongest return If the first return is also the strongest, then the even-number block stores the
second strongest return.
0x3E Strongest Second Strongest If there is only one return, then the two blocks store the same data.
0x3A First Second If there is only one return, then the two blocks store the same data.