AT128E2X Channel Hybrid Solid State Lidar

Product Information

Specifications

• Product Name: AT128E2X
• Channels: 128
• Lidar Type: Hybrid Solid-State Lidar
• Classification: Internal
• Document Version: A01-en-230920

Product Usage Instructions

1. Source of Absolute Time

The absolute time of the product can be sourced from PTP
(Precision Time Protocol). Ensure that the PTP clock source is
properly configured for accurate time synchronization.

2. Absolute Time of Point Cloud Data Packets

The product provides absolute time information for each Point
Cloud Data Packet. This information can be used for precise
timestamping and synchronization purposes.

3. Start Time of Each Block

Each block of data transmitted by the product has a start time
associated with it. This start time indicates when the data in that
block was captured.

4. Laser Firing Time of Each Channel

The product records the laser firing time for each channel. This
information helps in determining the timing of each laser
pulse.

Appendix C: Angle Correction

C.1. Data Format

The product uses a specific data format for angle correction
calculations. Ensure that the data format is correctly understood
and applied for accurate angle correction.

C.2. Angle Correction Calculation

The product provides angle correction calculations for accurate
measurement of distances. Follow the instructions in this section
to perform the angle correction calculations properly.

About this Manual

Please read through this user manual before using the product
for the first time. Follow the instructions provided to ensure safe
and proper use of the product. Failure to comply with the
instructions may result in product damage, property loss, personal
injuries, and/or a breach of warranty.

Access to this Manual

This manual can be accessed at www.hesaitech.com. Please refer to the
website for the latest version of the manual.

Technical Support

If you require technical support or have any questions regarding
the product, please contact Hesai Technology or an authorized Hesai
Technology service provider.

Legends

• Warnings: Instructions that must be followed
  to ensure safe and proper use of the product.

• Notes: Additional information that may be
  helpful.

Safety Notice

Hesai makes no warranty of non-infringement nor assumes any
responsibility for quality assurance.

Special Warnings

Laser Safety

Take necessary precautions to ensure laser safety when operating
the product. Follow all safety guidelines and regulations related
to laser usage.

Hot Surface

The product may have hot parts. Avoid touching these parts
immediately after operation. Wait for at least half an hour after
switching off the product before handling any parts to avoid
burns.

Prohibition of Disassembly

Unless expressly agreed to in writing by Hesai Technology, do
NOT disassemble the product. Disassembling the product without
proper authorization may void the warranty and result in product
damage.

FAQ

1. 1. Q: Where can I find the latest version of the user manual?

A: The latest version of the user manual can be found on the
Hesai Technology website at www.hesaitech.com.

1. 1. Q: What should I do if I have technical issues or need  

   support?

A: If you require technical support or have any questions
regarding the product, please contact Hesai Technology or an
authorized Hesai Technology service provider.

1. 1. Q: Can I disassemble the product?

A: Unless expressly agreed to in writing by Hesai Technology,
disassembling the product is prohibited. Unauthorized disassembly
may void the warranty and result in product damage.

www.hesaitech.com
AT128E2X
128-Channel Hybrid Solid-State Lidar User Manual
Classification: Internal Doc Version: A01-en-230920

Table of Contents
About this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Access to this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Technical support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Legends. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Formatting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Safety notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Special warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Operating environment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Installation and operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Repair and maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.1. Operating principle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.2. Lidar structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.3. Channel distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.4. Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2. Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.1. Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2. Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.2.1. Pin description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.2.2. Connector Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.2.3. Cables (Ethernet). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2.3. Connection box (optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.3.1. Connection box ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2.3.2. Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.4. Get ready to use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.4.1. Network settings on the receiving host . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.4.2. Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3. Data structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.1. Point cloud data packet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3.1.1. Ethernet header. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3.1.2. Point cloud UDP data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.1.3. Point cloud data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4. Web control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 4.1. Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 4.2. Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4.2.1. Network settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 4.2.2. Function settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 4.2.3. Time settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 4.3. Operation statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.4. Upgrade. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.5. Fault message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.6. Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5. Communication protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 6. Sensor maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 7. Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Appendix A: Channel distribution data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Appendix B: Absolute time of point cloud data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
B.1. Source of absolute time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 B.1.1. PTP as the clock source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
B.2. Absolute time of Point Cloud Data Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 B.3. Start time of each block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

B.4. Laser firing time of each channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Appendix C: Angle correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
C.1. Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 C.2. Angle correction calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
C.2.1. Horizontal angle of the current firing channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 C.2.2. Vertical angle of the current firing channel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Appendix D: Legal notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

About this manual
Please make sure to read through this user manual before your first use and follow the instructions herein when you operate the product. Failure to comply with the instructions may result in product damage, property loss, personal injuries, and/or a breach of warranty.
Access to this manual
To obtain the latest version, please try one of the following: · Visit the Download page of Hesai’s official website: https://www.hesaitech.com/downloads/ · Contact your sales representative at Hesai. · Contact Hesai’s technical support team: service@hesaitech.com
Technical support
If your question is not addressed in this user manual, please contact us at: · service@hesaitech.com · https://www.hesaitech.com/technical-support/ · https://github.com/HesaiTechnology (Please leave your questions under the corresponding GitHub projects.)
Legends
Warnings: Instructions that must be followed to ensure safe and proper use of the product. Notes: Additional information that may be helpful.
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Formatting
Monospace font: field names For example: Distance represents the Distance field.
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Safety notice
· Please check the certification information on the product’s nameplate and read through the corresponding certification warnings. If specific users require not to present certification information on the nameplate, please follow the agreed-to arrangements.
· If you incorporate this lidar product into your product(s), you are required to provide this user manual (or the means to access this user manual) to the intended users of your product(s).
· This lidar product is intended as a component of an end product. It is the responsibility of the end-product supplier to assess the risk of use in accordance with applicable standards and inform the intended user of safety- related information.
· Should there be other agreements with specific users, the other agreements shall apply. · Before using a product, please confirm with Hesai the development maturity of the product in a timely manner. For products still in development,
Hesai makes no warranty of non-infringement nor assumes any responsibility for quality assurance.
Special warnings
Laser safety
Hot surface
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Hot parts! Burned fingers when handling the parts. Wait one-half hour after switching off before handling the parts.
Abnormalities In any of the circumstances listed below, stop using the product immediately: · If you suspect malfunctions of or damage to the product. For example, the product generates significant noise or is visibly vibrating. · If you or people in the nearby environment feel discomfort. · If any device or equipment in the nearby environment malfunctions.
Meanwhile, contact Hesai Technology or an authorized Hesai Technology service provider for more information on product disposal.
Prohibition of disassembly Unless expressly agreed to in writing by Hesai Technology, do NOT disassemble the product.
Operating environment
Radio frequency interference · Before using the product, make sure to read all the signs and notices on the product enclosure (including the bottom plate). · Although the product is designed, tested, and manufactured to comply with the regulations on RF radiation (such as FCC, CE-EMC, or KCC), the
radiation from the product may still influence electronic devices.
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Vibration · If significant mechanical shocks and vibration exist in the product’s operating environment, please contact Hesai’s technical support team to
obtain the shock and vibration limits of your product model. Exposure to over- the-limit shocks or vibration may damage the product. · Make sure to package the product in shock-proof materials to avoid damage during transport.
Explosive atmosphere and other air conditions · Do NOT use the product in any area where potentially explosive atmospheres are present, such as environments with high concentrations of
flammable chemicals, vapors, or particulates (including particles, dust, and metal powder) in the air. · Do NOT expose the product to environments having high concentrations of industrial chemicals, including liquefied gases that are easily
vaporized (such as helium). Such exposure can damage or impair product functionality.
Chemical environment To prevent damage or impairment of product functionality, do NOT expose the product to corrosive liquids, including but not limited to strong acids, strong bases, esters, and ethers.
Ingress protection Please check the product’s user manual for its IP rating (refer to Section 1.4 Specifications). Make sure to avoid any ingress beyond that rating.
Operating temperature Please check the product’s user manual for its operating temperature (refer to Section 1.4 Specifications). Make sure not to exceed the operating temperature range.
Recommended storage conditions Please store the product in a dry and well- ventilated place. The recommended ambient temperature is 23 ± 5°C, and the humidity is between 30% and 70%.
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Light interference Certain precision optical instruments may interfere with the laser light emitted from the product. Please check all the instructions for these instruments and take preventive measures if necessary. For example, protective leather covers are provided for certain product models; when such products are temporarily not used for measurement, the leather covers can be applied to block laser light emission.
Personnel
Recommended operator qualifications The product should be operated by professionals with engineering backgrounds or experience in operating optical, electrical, and mechanical instruments. Please follow the instructions in this manual when operating the product and contact Hesai technical support if needed.
Medical device interference · Some components in the product can emit electromagnetic fields. If the product operators or people in the nearby environment wear medical
devices (such as cochlear implants, implanted pacemakers, and defibrillators), make sure to consult the physicians and medical device manufacturers for medical advice, such as determining whether keeping the product a safe distance away from the medical devices is needed. · If you suspect that the product is interfering with your medical device, stop using the product immediately.
Installation and operation
Power supply · You are recommended to use only the cables and power adapters provided by Hesai Technology. · If you are to design, configure, or select the power supply system (including cables) for the product, make sure to comply with the electrical
specifications in the product’s user manual (refer to Section 1.4 Specifications and the Power Supply Requirements section if available); for technical support, please contact Hesai Technology. Do NOT use off-spec or damaged cables or adapters.
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Electrical interface · Before powering on the product, make sure the electrical interfaces are dry and clean. Do NOT power on the product in humid conditions. · Please check the Interfaces section in the product’s user manual and strictly follow the instructions on plugging/unplugging the connector. If
abnormalities already exist (such as bent pins, broken cables, and loose screws), stop using the product and contact Hesai technical support. · To prevent breakdowns, turn off the power source before connection and disconnection. Eye safety The product is a Class 1 laser product. It satisfies the requirements of: · IEC 60825-1:2014 · EN 60825-1:2014+A11:2021 · 21 CFR 1040.10 and 1040.11 except for deviations (IEC 60825-1 Ed.3) pursuant to Laser Notice No.56, dated May 8, 2019. CAUTION: Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.
CAUTION · For maximum self-protection, it is strongly warned NOT to look into the transmitting laser through a magnifying product (microscope, eye
loupe, magnifying glass, etc.). · This product does not have a power switch. It starts operating once connected to power. During operation, the entire optical window can be
regarded as the product’s laser emitting window; looking at the optical window can be regarded as looking into transmitting laser.
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Product enclosure · The product contains metal, glass, plastic, as well as sensitive electronic components. If the product is dropped or burnt, stop using it
immediately and contact Hesai technical support. · Do NOT squeeze or pierce the product. If the product enclosure is broken, stop using it immediately and contact Hesai technical support. · Certain product models contain high-speed rotating parts. To avoid potential injuries, do NOT operate the product if the enclosure is loose. · Before operating the product, make sure it is properly and securely mounted. The mounting should prevent the product from leaving its
mounting position under external forces (such as collisions, high winds, and stone impacts). · If the product enclosure consists of fins or grooves, please wear gloves when handling the product. Applying too much pressure with your bare
hands may cause cuts, bruises or other injuries.
Product enclosure: optical window · Do NOT apply protective film, wax or any other substance on the optical window. · To keep the product’s optical window from fingerprints and other stains, do NOT touch the optical window with bare hands. If the optical
window is already stained, please refer to the cleaning method in the Sensor Maintenance section of the user manual. · To prevent scratches, do NOT touch the product’s optical window with hard or sharp objects. If scratches already exist, stop using the product
and contact Hesai technical support. Severe scratches may affect the quality of the product’s point cloud data. · Before installing any exterior part, please ensure that each exterior part and its movable area do not overlap the Field of View (FOV) of the lidar
product.
The FOV of lidar is the spatial angular range bounded by the horizontal and vertical FOV ranges (see Section 1.4 Specifications of the
product’s user manual); the distance to the origin of the lidar’s coordinate system is not limited. For inquiries about the FOV, please contact Hesai technical support.
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Hot surface
During operation or a time period after the operation, the product’s enclosure can be hot. · To prevent discomfort or even burns, do NOT touch the product’s enclosure with your skin. · To prevent fires, do NOT keep flammable materials away from the product’s enclosure. · If a hot surface sign is provided on the product’s enclosure, the product will be embedded into other equipment. Please make sure the sign is
not blocked from view. In case the sign is not visible from the outside, make sure to take effective measures to warn any third party of the hot surface hazards. Certain product models support active heating of the optical window to reduce the impact of ice and frost. Users can turn off this function. · While active heating is ON, please avoid direct skin contact with the optical window. · For each product model, the location of the optical window is illustrated in the Introduction section of the product’s user manual.
Peripherals
The product may be used along with accessories and devices, such as suction cup mounts, extension cables, power supplies, network devices, GPS/PTP devices, and cleaning equipment. Please refer to all relevant specifications in the product’s user manual, or contact Hesai technical support. Using off- spec or unsuitable devices may result in product damage or even personal injuries.
Firmware and software upgrading
Make sure to use only the upgrade files provided by Hesai Technology. Make sure to observe all the instructions provided for that upgrade file.
Customized firmware and software · Before using a customized version of firmware and software, please fully understand the differences in functions and performance between the
customized version and the standard version. · Make sure to strictly follow all the instructions and safety precautions provided for that customized version. If the product does not function as
anticipated, stop using the product immediately and contact Hesai technical support.
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Point cloud data processing · Certain product models support one or more point cloud data processing functions, including but not limited to: Noise Filtering, Interstitial
Points Filtering, Retro Multi-Reflection Filtering, and Non-Linear Reflectivity Mapping. · These functions are configurable and are intended only to assist the user in extracting information from the point cloud data. Users are in full
control of whether to use any of these functions. Moreover, users are responsible for analyzing the product’s intended application scenarios and evaluating the risk of enabling one or more of these functions in combination. · To learn about the supported functions of a product model, please contact Hesai technical support.
Repair and maintenance
For product repair or maintenance issues, please contact Hesai Technology or an authorized Hesai Technology service provider. Repair Unless expressly agreed to in writing by Hesai Technology, do NOT by yourself or entrust any third party to disassemble, repair, modify, or retrofit the product. Such a breach: · can result in product damage (including but not limited to water resistance failure), property loss, and/or injuries; · shall constitute a breach of warranty.
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1. Introduction
1.1. Operating principle
Distance measurement: Time of Flight (ToF) 1. A laser diode emits a beam of ultrashort laser pulses onto the target object. 2. The laser pulses are reflected after hitting the target object. The returning beam is detected by an optical sensor. 3. Distance to the object can be accurately measured by calculating the time between laser emission and receipt.
d: Distance c: Speed of light t: Travel time of the laser beam
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1.2. Lidar structure
The lidar structure is shown in Figure 3. Mirror rotation direction (top view). A rotating mirror is used to scan horizontally.

Figure 1. Front view

Figure 2. Coordinate system (isometric view)

Figure 3. Mirror rotation direction (top view)

· The lidar’s coordinate system is illustrated in Figure 2. Coordinate system (isometric view). The Z-axis is the axis of rotation. · The origin is shown in Figure 5. Origin of coordinates (unit: mm). All measurements are relative to the origin. · The mirror rotates clockwise in the top view, see Figure 3. Mirror rotation direction (top view). · Lidar azimuthal position is defined in Figure 3. Mirror rotation direction (top view). The Y-axis corresponds to 0°.

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1.3. Channel distribution
· The designed vertical resolution is 0.2° across the FOV, as shown in Figure 4. Channel vertical distribution and detailed in Appendix A Channel distribution data.
· Each channel has an intrinsic angle offset, both horizontally and vertically. The offset angles are recorded in this lidar unit’s angle correction file (see Appendix C Angle correction).

Figure 4. Channel vertical distribution

Figure 5. Origin of coordinates (unit: mm) -13-

1.4. Specifications

SENSOR Scanning method Channels Range capability Range accuracy Range precision FOV (horizontal) Resolution (horizontal)
FOV (vertical) Resolution (vertical) Frame rate Return modes

1-D rotating mirror (hybrid solid-state) 128 1 to 180 m (at 10% reflectivity) ±5 cm (typical) 3 cm (1) 120° 0.1° (10 Hz) 0.2° (20 Hz) 25.4° (-12.5° to 12.9°) 0.2° 10/20 Hz Single Return (Last/Strongest) Dual Return (Last and Strongest)

MECHANICAL/ELECTRICAL/OPERATIONAL

Wavelength

905 nm

Laser class

Class 1 Eye Safe

Ingress protection

IP6K7 & IP6K9K

Dimensions

136 x 112 x 48 (WDH, mm)

Rated voltage range

DC 9 to 32 V

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Power consumption Operating temperature Storage temperature Weight

18 W -40 to 85 -40 to 95 0.95 kg

DATA I/O Data transmission
Measurements Valid data points
Point cloud data rate
Clock source PTP clock accuracy PTP clock drift

UDP/IP automotive Ethernet, 1000BASE-T1 Slave Mode
Distance, azimuth angle and reflectivity
Single Return 1 536 000 points/sec Dual Return 3 072 000 points/sec
Single Return 55.7/111.4 Mbps (avg/peak) Dual Return 111.4/222.8 Mbps (avg/peak)
PTP
1 s
5 s/s

Specifications are subject to change. Please refer to the latest version.

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Notes to the specifications

Dimensions and weight Rated Voltage Range
Power consumption Valid Data Points

May be different for customized models. The mechanical drawings and data exclusively provided for customized models shall prevail.
· Lidar with 24 V nominal voltage: DC 9 to 32 V. · Lidar with 12 V nominal voltage: DC 9 to 16 V. · Nominal voltage: shown on the Home page of web control (see Section 4.1 Home).
· Typical value, not including accessories such as the connection box. · The external power supply should be able to provide at least 45 W.
· Point cloud data points (i.e. number of returns) generated per second. · In Single Return Mode:
Given: horizontal FOV (120°), horizontal resolution (0.1° at 10 Hz), number of channels (128), and frame rate (10 Hz).
At 10 Hz, each channel generates 120/0.1 = 1200 points per frame; all channels generate 1200 * 128 = 153 600 points per frame, and 1 536 000 points (10 frames) per second.
· In Dual Return Mode, the number of valid data points is twice that in Single Return Mode. · The actual horizontal FOV of each mirror surface is slightly larger than 120°, so the actual data points are
slightly more than the valid data points.

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Point cloud data rate PTP clock drift

· In Single Return Mode: Given: horizontal FOV (120°), horizontal resolution (0.1° at 10 Hz), frame rate (10 Hz), size of Point Cloud Data Packets (1160 bytes) and the number of blocks in each packet (2) At 10 Hz, one return is generated for each 0.1° azimuth; thus 1200 (120°/0.1°) returns for each frame and 12000 returns (10 frames) per second. Each Point Cloud Data Packet contains two blocks, and each block stores one return. Therefore, 12000/2 = 6000 packets are transmitted per second, totaling 6000 1160 bytes With unit conversion, point cloud average data rate = 6000 1160 8 1E-6 55.7 Mbps.
· In Dual Return Mode, point cloud average data rate is twice that in Single Return Mode. · Since the duty cycle for point cloud data transmission is approximately 50%, the peak data rate is
approximately twice the average data rate in the table.
Defined as the drift at a constant temperature after the lidar (slave clock) loses connection to the PTP master.

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2. Setup
2.1. Mechanical Installation

Figure 6. Front view (unit: mm)

Figure 7. Right side view (unit: mm)

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Figure 8. Bottom view (unit: mm)
The information in this section may be different for customized models. The mechanical drawings and data exclusively provided for customized models shall prevail.
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2.2. Interfaces
TE Connectivity part number: 2387351-1 (male socket, on the lidar)
Figure 9. TE connector (male socket): dimensions and pin number
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2.2.1. Pin description
No. 1 2 3 4 5 6 D2 D1

Signal VCC GND MDI-P
MDI-N

· Lidar with 24 V nominal voltage: DC 9 to 32 V. · Lidar with 12 V nominal voltage: DC 9 to 16 V. · Nominal voltage: shown on the Home page of web control (see Section 4.1 Home).

Avoid touching the reserved wires or ports with bare hands.

Voltage 9 to 32 V
0 V –

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2.2.2. Connector Use

Figure 10. Connectors

Connection
1. Turn off the power source. 2. Make sure the plug’s red locking clip is on the same side as the
socket’s latch. 3. Push the plug straight into the socket until a click is heard. 4. Push down the red locking clip to the bottommost position until a
click is heard.

Disconnection
1. Turn off the power source. 2. Pull up the red locking clip with your fingernail until a click is heard. 3. Push down the black clip and pull the plug from the socket.

· DO NOT attempt to force open a connection by pulling on the cables or by twisting the connectors in any way. Doing so can loosen the connectors’ shells, or even damage the contacts.
· If the connector’s shell is accidentally pulled off, stop using the connector and contact Hesai technical support. · DO NOT attempt to assemble the connector’s shell and cable collet; DO NOT connect a connector without its shell. Doing so may damage

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the lidar’s circuits. · Before connection, check the pins on the socket and the holes on the plug. If bent pins or damaged holes occur, stop using the connector
and contact technical support. · The connector supports at least 20 mating cycles. Exceeding this limit may result in connector damage.

Figure 11. Connection

Figure 12. Disconnection

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2.2.3. Cables (Ethernet)
OD (outside diameter) = 4.10 ± 0.20 mm Minimum bend radius: Single: 5 OD Multiple: 15 OD
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2.3. Connection box (optional)
Users may connect the lidar directly or using the connection box.
Figure 13. Connection box (unit: mm) -25-

An additional cable is used for connecting the lidar (on the left) and the connection box (on the right), as shown below.
One cable’s head cannot connect to another cable’s tail, so each lidar can only use one cable.

Pin # on CNT1 Connector Pin 1 Pin 4
Pin # on CNT1 Connector D2 D1

Figure 14. Cable between Lidar and Connection Box (unit: mm)

The wire colors and cross-section areas are listed below:

Pin # on CNT3 Connector

Signal

Wire Color

Pin 4

VCC

Red

Pin 8

GND

Black

Pin # on CNT2 Connector
Pin 1
Pin 2

Signal
MDI-P MDI-N

Wire Color
White Green

Wire Cross Section
0.75 mm^2 0.75 mm^2 Wire Cross Section
–

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2.3.1. Connection box ports

Port # a b c

Port Name Standard Ethernet port Power port Reserved port

Figure 15. Connection Box (Front)
Description RJ45, 1000 Mbps Ethernet Connects to a DC-005 DC power adapter. Do not connect this port to external signals.

Port # d e f

Figure 16. Connecting Box (Back)

Port Name Reserved port Power Output port Automotive Ethernet port

Description Do not connect this port to external signals See CNT3 connector in Figure 14. Cable between Lidar and Connection Box (unit: mm). See CNT2 connector in Figure 14. Cable between Lidar and Connection Box (unit: mm).

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2.3.2. Connection
Figure 17. Connection with PTP (software simulation) -28-

Figure 18. Connection with PTP (hardware device) -29-

2.4. Get ready to use
Before operating the lidar, strip away the transparent protective film on the optical window. The lidar does not have a power switch. It starts operating once connected to power and the Ethernet.

2.4.1. Network settings on the receiving host
To receive data on your PC, set the PC’s IP address to 192.168.1.X and subnet mask to 255.255.255.0.
Range of X: 0 to 255 (except 201, 1 and 255)

Ubuntu
1. Open terminal. 2. Input this ifconfig command in the terminal:
~$ sudo ifconfig enp0s20f0u2 192.168.1.X (replace enp0s20f0u2 with the local Ethernet port name)

Windows
1. Open the Network Sharing Center and click “Ethernet”. 2. In the “Ethernet Status” box, click “Properties”. 3. Double-click “Internet Protocol Version 4 (TCP/IPv4)”. 4. Configure the IP address to 192.168.1.X and the subnet mask to
255.255.255.0.

2.4.2. Tools
· To record and display point cloud data, see PandarView 2 User Manual. · To set parameters, check device info or upgrade firmware/software, use either web control or PTC commands. · To obtain the SDKs (Software Development Kits) for your product model, please visit Hesai’s official GitHub page: https://github.com/
HesaiTechnology

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3. Data structure
The lidar outputs Point Cloud Data Packets. Unless otherwise specified, all the multi-byte fields are unsigned values in little-endian format.

Lidar Data

Point Cloud Data Packet: 1160 bytes

Ethernet Header: 42 bytes UDP Data: 1118 bytes

pre-Header: 6 bytes Header: 6 bytes Body: 1034 bytes Tail: 40 bytes Cyber Security: 32 bytes

Figure 19. Data structure

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3.1. Point cloud data packet

3.1.1. Ethernet header
Default IP address: Source IP Destination IP

192.168.1.201 255.255.255.255

Point Cloud Data Packet: Ethernet header

Field

Bytes

Ethernet II MAC

12

Ethernet Data Packet Type

2

Internet Protocol

20

UDP Port Number

4

UDP Length

2

UDP Checksum

2

Description Destination MAC: xx:xx:xx:xx:xx:xx (FF:FF:FF:FF:FF:FF for broadcast) Source MAC: xx:xx:xx:xx:xx:xx 0x08, 0x00 Protocol parameters UDP source port (0x2710, representing 10000) Destination port (0x0940, representing 2368) 8 bytes more than point cloud UDP data, see Figure 19. Data structure. Checksum of the Ethernet Header

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3.1.2. Point cloud UDP data

3.1.2.1. Pre-header
Field 0xEE 0xFF Protocol Version Major

Bytes 1 1 1

Protocol Version Minor

1

Reserved

2

Description SOP SOP Main class of the point cloud UDP packet structure Current value: 0x04 Subclass of the point cloud UDP packet structure Current value: 0x03 –

3.1.2.2. Header
Field Laser Num Block Num First Block Return Dis Unit Return Num

Bytes 1 1 1 1 1

Description Fixed: 0x80 (128 channels) Fixed: 0x02 (2 blocks per packet) Reserved Fixed: 0x04 (4 mm) Fixed: 0x02 (Each channel can generate two returns maximum.)

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Field Flags
3.1.2.3. Body Field Azimuth 1
Fine Azimuth 1
Block 1

Bytes 1

Description [7:4] is reserved Bit [3] digital signature [2] functional safety [1] IMU [0] UDP sequence

Value 1–Yes 1–Yes 1–Yes 1–Yes

0–No 0–No 0–No 0–No

Bytes 2 1
512

Description For Block 1: Low-resolution part of the encoder angle Unit: 0.01°
The encoder angle is measured by the optical encoder, used as the current reference angle of the azimuth.
For Block 1: High-resolution part of the encoder angle Unit: 0.01° / 256 Encoder angle of Block 1 = Azimuth 1 0.01° + Fine Azimuth 1 0.01° / 256
To convert from encoder angle to point cloud horizontal angle (see Appendix A Channel distribution data).
For Block 1: measurements made by each channel, starting from Channel 1 (see the table below).

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Field Azimuth 2 Fine Azimuth 2 Block 2 CRC 1

Bytes 2 1 512 4

Description Block 2
CRC-32 checksum of the Body

Each block in the Body Field Channel X

Bytes 4

Description
Object distance = Distance Dis Unit
Dis Unit is specified in Section 3.1.2.2 Header.
Reflectivity Value = Reflectivity 1% Range: 0 to 255 Low confidence flag, showing the confidence of the return signal. Range: 1 (low confidence), 0 (normal)
Low-confidence data points can be allowed or filtered out by sending PTC commands (see
Section 5 Communication protocol); allowing such points improves the detection of lowreflectivity objects.

In Dual Return mode, the measurements from each round of firing are stored in two adjacent blocks:
· The odd-numbered block is the last return, and the even-numbered block is the strongest return. · If the last and strongest returns coincide, the second strongest return will be placed in the even-numbered block. · The Azimuth (encoder angle) changes every two blocks.

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Point Cloud Data Packet (Single Return)

Block 1

Block 2

Return from this round of firing

Return from the next round of firing

Point Cloud Data Packet (Dual Return)

Block 1

Block 2

Last return

Strongest return

Point Cloud Data Packet (Dual Return)

Block 1

Block 2

Last and strongest return

Second strongest return

3.1.2.4. Tail
Field Reserved High Temperature Shutdown Flag

Bytes 6 1

Reserved

11

Motor Speed

2

Description
–
0x01 for high temperature; 0x00 for normal operation.
· When a high temperature is detected, the shutdown flag will be set to 0x01, and the system will shut down after 60 s. The flag remains 0x01 during the 60 s and the shutdown period.
· When the system is no longer in high temperature status, the shutdown flag will be reset to 0x00 and the system will automatically return to normal operation.
–
Spin rate of the motor Signed integer Define clockwise in the top view as positive. Unit: 0.1 RPM

· By default, each of the three mirror surfaces corresponds to a point cloud frame. Thus for every motor rotation, three frames are generated.
· Spin rate of the motor (RPM) = frame rate (Hz) * (60/3)

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Field Timestamp
Return Mode Factory Information Date & Time
UDP Sequence CRC 2 3.1.2.5. Cyber security

Bytes 4
1 1 1 * 6
4 4

Description
The “s time” part of the absolute time of this data packet Unit: s Range: 0 to 999 999 s (1 s)

To see the definition of absolute time, please refer to Appendix B Absolute time of point cloud data.

0x37–Strongest Return Mode 0x38–Last Return Mode 0x39–Dual Return Mode (Last & Strongest)
Fixed: 0x42
The absolute time of this data packet, accurate to the second.

In big-endian format:

Byte 1 Byte 2 to 6

0x00 (fixed) Number of seconds since the Unix epoch (1970-01-01 00:00:00 UTC)

To see the definition of absolute time, please refer to Appendix B Absolute time of point cloud data.
Sequence number of this UDP packet 0 to 0xFF FF FF FF CRC-32 checksum of the Tail

-37-

Field Signature

Bytes 32

Description
Point cloud signature Calculated using Point Cloud UDP Data (from Pre-Header to Tail) Algorithm: CMAC (128 bits) or HMAC-SHA256 (256 bits)
This field is not yet supported.

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3.1.3. Point cloud data analysis
The analysis of point cloud UDP data consists of three steps. 3.1.3.1. Analyze the vertical and horizontal angles of a data point Take Channel 5 in Block 2 as an example: 1. Calculate the vertical angle (v_angle) of Channel 5 according to Appendix C Angle correction.
0° represents the horizontal direction. Define upward as positive. Channel # from the uppermost counts from 1. 2. Calculate the horizontal angle (h_angle_0) of Channel 5 according to Appendix C Angle correction. Define clockwise in the top view as positive. 3. For each channel, a firing time offset translates to an offset in the horizontal angle.
h_angle = h_angle_0 + firing time angular offset firing time angular offset = firing time offset of Channel 5 spin rate of the motor 2 · Firing time offset: in units of s (seconds); see Section B.4 Laser firing time of each channel. · Spin rate of the motor: in units of °/s (degrees per second); see Section 4 Web control. 3.1.3.2. Analyze the distance of a data point Use the Distance field of Block 2: Channel 5 in Section 3.1.2.3 Body.
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3.1.3.3. Draw the data point in a spherical or rectangular coordinate system In a spherical coordinate system, the vertical and horizontal angles are defined in the figure below.
3.1.3.4. Obtain the real-time point cloud data by analyzing and drawing every data point in each frame
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4. Web control

Web control is used for setting parameters, checking device info, and upgrading.

To access web control,
1. Connect the lidar to your PC using an Ethernet cable. 2. Set the IP address according to Section 2.4 Get ready to use. 3. Enter this URL into your web browser: 192.168.1.201.

· May be different for customized models. The mechanical drawings and data exclusively provided for customized models shall prevail. · Google Chrome and Mozilla Firefox are recommended. · Firewall port exceptions: Port 9347 (PTC/PTCS), Port 80 (HTTP), Port 443 (HTTPS), and Ports 319 and 320 (PTP 1588v2)

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4.1. Home

Status Spin Rate PTP Device Info Model S/N MAC Address Software Version Firmware Version RPU Version Nominal Voltage PHY Mode

200 RPM Free Run
AT128E2X ATXXXXXXXXXXXXXX XX:XX:XX:XX:XX:XX 3.50.15 3.10b830 3.50.008 24 V Slave

Device Log

-42-

Parameter Spin Rate PTP
Firmware Version RPU Version
Nominal Voltage PHY Mode

Description
· Options: 200/400 RPM · Detailed in the Motor Speed field in Section 3.1.2 Point cloud UDP data.

PTP status

Free Run Tracking
Locked Frozen (Holdover)

No PTP master is selected. Attempting to sync with the selected PTP Master, but the absolute offset exceeds the user-specified limit in Section 4.2.3 Time settings. Absolute offset is within the user-specified limit. Attempting to recover the connection to the PTP master.

Version number of FPGA
· Version number of RPU* RPU (real-time processing unit) is mainly used in:
· Diagnosis for functional safety · Loading and configuration for point cloud parameters
· Lidar with 24 V nominal voltage: DC 9 to 32 V · Lidar with 12 V nominal voltage: DC 9 to 16 V
Communication mode for automotive Ethernet (1000Base-T1)
· Master · Slave (by default)

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4.2. Settings

Control IP IPv4 Address IPv4 Mask IPv4 Gateway VLAN Settings Destination IP Lidar Destination Port Fault Message Destination Port Spin Rate Return Mode Sync Angle Trigger Method Clock Source
Profile Time Offset for Lidar Lock PTP Network Transport PTP Domain Number PTP logAnnounceInterval

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Reset All Settings
192.168.1.201 255.255.255.0
192.168.1.1 0
255.255.255.255 2368 2368
200 RPM Strongest
0 Angle Based
PTP 1588v2
1 UDP/IP
0 1

PTP logSyncInterval PTP logMinDelayReqInterval Standby Mode Lidar Work Mode Lidar Fault Status

Save

1 0 In Operation Standard Normal

Button Reset All Settings
Save

Description Reset all the configurable parameters to factory defaults, including: · Section 4.2 Settings. Save and execute all the settings on this page. Exception: Standby Mode takes effect immediately without having to click this button.

-45-

4.2.1. Network settings

Parameter VLAN

Options
Default: OFF VLAN ID: 1 to 4094

Description To enable VLAN tagging: · Make sure the receiving host also supports VLAN. · Check the checkbox and input the lidar’s VLAN ID (same as the receiving host’s VLAN
ID).
If the lidar’s VLAN ID differs from the receiving host’s, users will lose access to web control.

Destination IP
Lidar Destination Port Fault Message Destination Port

Once configured, the VLAN ID does not change during firmware upgrades.

· Any address except for 0.0.0.0, 127.0.0.1, and the lidar’s IP.
· Default: 255.255.255.255

IP Mode Broadcast (default)

Multicast

Unicast

Destination IP 255.255.255.255 User-defined Same as the PC’s IP address

Default: 2368 Default: 2368

Destination port of Point Cloud Data Packets Destination port of fault messages

-46-

4.2.2. Function settings

Parameter Spin Rate Return Mode
Sync Angle

Options 200/400 RPM Default: 200 RPM Single Return · Last · Strongest (by default) Dual Return · Last and Strongest 30° to 150°

Trigger Method

Angle-Based (default) Time-Based

Standby Mode

In Operation (Default)

Description The set spin rate is also shown on the Home page (see Section 4.1 Home).
Return Mode Also shown in Point Cloud Data Packets (see the Return Mode field in Section 3.1.2 Point cloud UDP data).
Phase lock angle · To activate this function, check the checkbox and input an azimuth. · At every full second, the lidar will rotate to that azimuthal position (see Section
1.2 Lidar structure). Definition of the full second: · When PTP is tracking or locked: retrieved from the PTP master clock · Otherwise: the rising edge of the lidar’s internal 1 Hz signal · Detailed in Appendix B Absolute time of point cloud data. To phase-lock multiple lidars, Connect the lidars to the same clock source and set the same sync angle, and these lidars will rotate to that same azimuthal position at every full second. The way laser firings are triggered. Angle-Based Lasers fire every 0.1° at 10 Hz. Time-Based Lasers fire every 41.666 us. Standby In Standby mode, the motor stops running and lasers stop firing.
-47-

Parameter Lidar Work Mode
Lidar Fault Status

Options
Standard (Default) Standby Energy-Saving High-Temp-Shutdown Shutdown
Normal (Default) Fault-High-Temp-Shutdown Fault-Energy-Saving Fault-Shutdown

Description –
–

-48-

4.2.3. Time settings
Clock Source Profile Time Offset for Lidar Lock PTP Network Transport PTP Domain Number PTP logAnnounceInterval PTP logSyncInterval PTP logMinDelayReqInterval

Parameter Clock Source Profile
Time Offset for Lidar Lock PTP Network Transport

Options
fixed: PTP
1588v2 (by default) 802.1AS 802.1AS Automotive
1 to 100 s (integer) Default: 1
UDP/IP(by default) L2

Domain Number

0 to 127 (integer) Default: 0

PTP 1588v2 1 UDP/IP 0 1 1 0
Description External source of absolute time IEEE timing and synchronization standard

Specify the upper limit of the absolute offset between Slave and Master when the lidar is in PTP Locked status; see Section 4.1 (Home)
Network transport protocol

UDP/IP L2

Available only for 1588v2 profile Available for all profiles

Domain attribute of the local clock

-49-

When using the 1588v2 profile:: Parameter PTP logAnnounceInterval
PTP logSyncInterval
PTP logMinDelayReqInterval

Options -2 to 3 (Default: 1)
-7 to 3 (Default: 1)
-7 to 3 (Default: 0)

Description
Time interval between Announce messages Default: 1 log second (2 seconds)
Time interval between Sync messages Default: 1 log second (2 seconds)
Minimum permitted mean time between Delay_Req messages Default: 0 log second (1 second)

-50-

4.3. Operation statistics
These operating parameters are shown in real time: Start-up Counts Internal Temperature Internal Humidity Total Operation Time Internal Temperature < -40 -40 to -20 … 100 to 120 >120

510 32.10 50.0% RH 559 h 43 min Operation Time 0 h 1 min 0 h 46 min … 1 h 44 min 0 h 0 min

-51-

4.4. Upgrade

Preparation · Please contact Hesai technical support to receive the upgrade file. · During the upgrade, it is recommended to place a protective cover or other opaque material over the lidar’s optical window.
Upgrade · Click the [Upload] button and select an upgrade file. · When the upgrade is complete, the lidar will automatically reboot, and the past versions will be logged in the Upgrade Log.
Buttons

Upload Restart

To upload the upgrade file
Software reboot Afterwards, the Start-Up Counts in the Operation Statistics page increments by 1; see Section 4.3 Operation statistics.

Parameter Software Version Firmware Version RPU Version

Current Version 3.50.15 3.10b830 3.50.008

Upgrade Log

–

Description Version number of FPGA Version number of RPU (real-time processing unit)
RPU is mainly used in:
· Diagnosis for functional safety
· Loading and configuration for point cloud parameters
–

The above version numbers may be different from the actual. Please refer to the web page of the lidar used.

-52-

4.5. Fault message
A freeze frame records the lidar’s status information when a fault occurs and is used in diagnostic analysis. Some of the fields are shown on this page. For more information on the complete freeze frame (527 bytes), please contact Hesai technical support.
Freeze Frame Info freeze_frame_0: cnts: 0 event_id: 0 OCC: 0 agingcnt: 0 recover_counter: 0 operation_cycle1: 1 operation_cycle3: 1 operation_cycle4: 0 operation_cycle6: 0 status_indicator30: 0 timestamp 20: 4252631040 timestamp21: 4253089795 event_state: 3 status_data: 00000000000000002f7f0700000000004000000002f7f07000000000040000000400000000 00 freeze_frame_1:
-53-

4.6. Log

The process logs on this page can be used for software troubleshooting. Button description

Clear ALL Download ALL

Clear all logs (not yet supported) Download all logs

-54-

5. Communication protocol
To acquire Hesai lidar’s PTC (Pandar TCP Commands) and HTTP API Reference Manual, please contact Hesai technical support.
-55-

6. Sensor maintenance

Stains on the lidar’s optical window, such as dirt, fingerprints, and oil, can negatively affect point cloud data quality. Before cleaning the optical window, please notice:
· Turn OFF the power source before cleaning. · To avoid damaging the optical coating, do NOT apply pressure when wiping the optical window.

· Only clean the stained area of the optical window. · Check before using a lint-free wipe or a soft sponge. If the wipe is stained, use another.

Please perform the following steps to remove the stains:
1. Thoroughly wash your hands or wear a pair of powder-free PVC gloves. Hold the metal lid and base of the lidar to avoid touching the optical window directly.
2. To remove dust, blow dry air onto the optical window, or use a piece of lint-free wipe or soft sponge to lightly brush across the dusty area. To remove persistent stains, move on to the next step.
3. Spray the optical window with warm, neutral solvent using a spray bottle.

Solvent type

Mild soap solution
Maximum two tablespoons of soap in 1 quart (1 liter) of water.

Solvent temperature

20 to 25

4. When the stains have loosened, dip a piece of lint-free wipe or soft sponge into the solvent made in Step 3, and gently wipe the optical window back and forth along its surface.
5. Should another cleaning agent be applied to remove certain stains, repeat Steps 3 and 4. 6. Spray the optical window with clean water, and gently wipe off the remaining liquid with another piece of lint-free wipe or soft sponge.

-56-

7. Troubleshooting

If the following procedures cannot solve your problem, please contact Hesai technical support.

Symptoms Indicator light is off on the connection box
Motor is not running

Points to check
Make sure that the following conditions are met:
· The power adapter is properly connected and in good condition; · The connection box is intact; · Input voltage and current satisfy the requirements in Section 2.3 Connection box (optional).
Power on again to check if the symptom persists.
Make sure that the following conditions are met:
· The power adapter is properly connected and in good condition. · If a connection box is used, the connection box is intact. · Input voltage and current satisfy the requirements in Section 1.4 Specifications and Section 2.3 Connection box
(optional). · web control can be accessed (see Cannot open web control); · the lidar is not in standby mode; this can be queried using either web control or PTC commands.
Power on again to check if the symptom persists.

-57-

Symptoms

Points to check

Make sure that the following conditions are met:

Motor is running but no output data is received, neither on Wireshark nor on PandarView 2

· Ethernet cable is properly connected (by unplugging and plugging again). · Destination IP is correctly set (using either web control or PTC commands). · Horizontal FOV is properly set (using either web control or PTC commands). · Firmware of Sensor Version is correct; this can be queried using either web control or PTC commands. · The lidar is emitting laser light; this can be checked by using an infrared camera, an infrared sensor card, or a
phone camera without an infrared filter.
If a connection box is used, replace the current Ethernet cable with another cable of at least Cat 6; Cat 7 or higher is recommended.

Can receive data on Wireshark but not on PandarView 2
Cannot open web control

Power on again to check if the symptom persists.
Make sure that the following conditions are met:
· Lidar Destination Port is correctly set (using either web control or PTC commands). · The PC’s firewall is disabled, or that PandarView 2 is added to the firewall exceptions. · The latest PandarView 2 is installed on the PC (see Download page of Hesai’s official website or contact Hesai
technical support).
Power on again to check if the symptom persists.
Make sure that the following conditions are met:
· Ethernet cable is properly connected (by unplugging and plugging again). · The lidar’s IP is in the same subnet with the PC’s (WireShark may be used to check the lidar’s IP that broadcasts
data packets).
Afterwards, follow the steps below:
· Restart the PC, or connect the lidar to another PC; · Power on again to check if the symptom persists.

-58-

Symptoms
Abnormal packet size (missing packets)
Abnormal point cloud (obviously misaligned points, flashing points, or incomplete FOV)

Points to check
Make sure that the following conditions are met:
· Azimuth FOV is properly set (using either web control or PTC commands); · Spin Rate is steady; this can be queried using either web control or PTC commands. · The lidar’s internal temperature is between -40 and 110; this can be queried using either web control or PTC
commands. · Ethernet is not overloaded; · No switch is connected to the network (the data transmitted from other devices may cause network congestion
and packet loss).
Afterwards, follow the steps below:
1. Connect the PC only to the lidar and check for packet loss. 2. Power on again to check if the symptom persists.
Make sure that the following conditions are met:
· The lidar’s optical window is clean. If not, refer to Section 6 Sensor maintenance for the cleaning method. · The lidar’s angle correction file is imported (refer to PandarView 2 User Manual). · Azimuth FOV is properly set (using either web control or PTC commands). · Spin Rate is steady; this can be queried using either web control or PTC commands. · The lidar’s internal temperature is between -40 and 110; this can be queried using either web control or PTC
commands.
Afterwards, follow the steps below:
1. Check for packet loss. 2. If no packet is missing and the point cloud flashes, please update PandarView 2 to the latest version (see
Download page of Hesai’s official website or contact Hesai technical support); and then restart the PC.
If the point cloud is still abnormal, connect the lidar to another PC and power on again to check if the symptom persists.

-59-

Appendix A: Channel distribution data

Notes to the table

Channel No. Angular position Instrument range Near- and mid-field enabled
Max. range @10% reflectivity
Far-field enhanced

Counts from 1, top to bottom.
The design values of each channel’s horizontal (azimuth) angle offset and vertical (elevation) angle.
· The accurate values are recorded in this lidar unit’s calibration file. · Refer to Section 3.1.3 Point cloud data analysis for the data analysis scheme.
Actual measurement range, confined by the allocated Time of Flight (ToF) for each channel
The 32 channels with min. instrument range = 0.5 m are near-field-enabled channels.
· All channels fire laser pulses that measure the far field (>7.2 m) · Additionally, the near-field-enabled channels also fire laser pulses that measure only the near field (0.5
to 7.2 m), at a time other than these channels’ far-field firings. · The horizontal resolution of near-field measurement is always 0.2° at 10 Hz and 0.4° at 20 Hz.
· Probability of Detection (PoD) = 50% · The values in brackets only indicate range capability, while the actual measurement range is cut off to
max. instrument range. · Channels 97 to 128 have enhanced near- and mid-field detection, since these channels typically point to
the ground in the far field.
Channels 33 to 96 are far-field-enhanced channels, able to detect 180 m@10% (see data in max. range @10% reflectivity).

-60-

Channel No.
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

Angular position

Horiz. offset

Vertical

2.4

12.93

-0.65

12.73

2.4

12.53

-0.65

12.33

2.4

12.13

-0.65

11.93

2.4

11.73

-0.65

11.53

2.4

11.33

-0.65

11.13

2.4

10.93

-0.65

10.73

2.4

10.53

-0.65

10.33

2.4

10.13

-0.65

9.93

-2.4

9.73

0.65

9.53

-2.4

9.33

0.65

9.13

Instrument range

Min

Max

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

-61-

Near-field enabled?
YES YES YES YES YES –

Max. range @10% reflectivity
–

Far-field enhanced?
–

Channel No.
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Angular position

Horiz. offset

Vertical

-2.4

8.93

0.65

8.73

-2.4

8.53

0.65

8.33

-2.4

8.13

0.65

7.93

-2.4

7.73

0.65

7.53

-2.4

7.33

0.65

7.13

-2.4

6.93

0.65

6.73

2.4

6.53

-0.65

6.33

2.4

6.13

-0.65

5.93

2.4

5.73

-0.65

5.53

2.4

5.33

-0.65

5.13

Instrument range

Min

Max

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

-62-

Near-field enabled?
YES YES YES YES YES –

Max. range @10% reflectivity
180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m

Far-field enhanced?
YES YES YES YES YES YES YES YES

Channel No.
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Angular position

Horiz. offset

Vertical

2.4

4.93

-0.65

4.73

2.4

4.53

-0.65

4.33

2.4

4.13

-0.65

3.93

2.4

3.73

-0.65

3.53

-2.4

3.33

0.65

3.13

-2.4

2.93

0.65

2.73

-2.4

2.53

0.65

2.33

-2.4

2.13

0.65

1.93

-2.4

1.73

0.65

1.53

-2.4

1.33

0.65

1.13

Instrument range

Min

Max

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

-63-

Near-field enabled?
YES YES YES YES YES –

Max. range @10% reflectivity
180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m

Far-field enhanced?
YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES

Channel No.
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

Angular position

Horiz. offset

Vertical

-2.4

0.93

0.65

0.73

-2.4

0.53

0.65

0.33

2.4

0.13

-0.65

-0.07

2.4

-0.27

-0.65

-0.47

2.4

-0.67

-0.65

-0.87

2.4

-1.07

-0.65

-1.27

2.4

-1.47

-0.65

-1.67

2.4

-1.87

-0.65

-2.07

2.4

-2.27

-0.65

-2.47

2.4

-2.67

-0.65

-2.87

Instrument range

Min

Max

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

-64-

Near-field enabled?
YES YES YES YES YES –

Max. range @10% reflectivity
180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m

Far-field enhanced?
YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES

Channel No.
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

Angular position

Horiz. offset

Vertical

-2.4

-3.07

0.65

-3.27

-2.4

-3.47

0.65

-3.67

-2.4

-3.87

0.65

-4.07

-2.4

-4.27

0.65

-4.47

-2.4

-4.67

0.65

-4.87

-2.4

-5.07

0.65

-5.27

-2.4

-5.47

0.65

-5.67

-2.4

-5.87

0.65

-6.07

2.4

-6.27

-0.65

-6.47

2.4

-6.67

-0.65

-6.87

Instrument range

Min

Max

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

200 m

7.2 m

200 m

0.5 m

200 m

7.2 m

200 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

-65-

Near-field enabled?
YES YES YES YES YES –

Max. range @10% reflectivity
180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m 180 m
–

Far-field enhanced?
YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES YES
–

Channel No.
101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

Angular position

Horiz. offset

Vertical

2.4

-7.07

-0.65

-7.27

2.4

-7.47

-0.65

-7.67

2.4

-7.87

-0.65

-8.07

2.4

-8.27

-0.65

-8.47

2.4

-8.67

-0.65

-8.87

2.4

-9.07

-0.65

-9.27

-2.4

-9.47

0.65

-9.67

-2.4

-9.87

0.65

-10.07

-2.4

-10.27

0.65

-10.47

-2.4

-10.67

0.65

-10.87

Instrument range

Min

Max

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

-66-

Near-field enabled?
YES YES YES YES YES –

Max. range @10% reflectivity
–

Far-field enhanced?
–

Channel No.
121 122 123 124 125 126 127 128

Angular position

Horiz. offset

Vertical

-2.4

-11.07

0.65

-11.27

-2.4

-11.47

0.65

-11.67

-2.4

-11.87

0.65

-12.07

-2.4

-12.27

0.65

-12.47

Instrument range

Min

Max

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

7.2 m

90 m

7.2 m

90 m

0.5 m

90 m

7.2 m

90 m

Near-field enabled?
YES YES –

Max. range @10% reflectivity
–

Far-field enhanced?
–

-67-

Appendix B: Absolute time of point cloud data

B.1. Source of absolute time
The lidar retrieves the current absolute time by connecting to an external clock source.

B.1.1. PTP as the clock source

The lidar connects to a third-party PTP master to obtain the absolute time.
· PTP can be configured using either web control or PTC commands. · PTP signal status can be queried using either web control or PTC commands. · No GPS Data Packets.
The absolute time is updated as follows:

PTP status
Free run
Tracking or Locked Frozen

Date and time (accurate to the second) Virtual
Synchronized Drifting

Lidar behavior
Since the lidar has not been locked before, it starts counting from a virtual UTC (such as 2000-01-01 00:00:00) using the lidar’s internal 1 Hz signal. The lidar extracts the actual date and time from the PTP Master’s messages. When the lidar goes from Tracking/Locked to Frozen, it starts counting from the last synchronized time using the lidar’s internal 1 Hz signal. This absolute time will gradually drift from the actual PTP time.

· PTP is a Plug & Play protocol; the lidar works as a PTP slave device and requires no additional setup. · The Timestamps and Date & Time fields in Point Cloud Data Packets strictly follow the PTP master device. Certain PTP master devices
may have a specified offset from the lidar’s time output. Please verify the configuration and calibration of your PTP master device.

-68-

B.2. Absolute time of Point Cloud Data Packets
The Absolute time of Point Cloud Data Packets is t0 = ts + tms, where: · ts is the whole second part (see the Date & Time field). · tms is the microsecond part (see the Timestamp field). The definition of the above fields is in Section 3.1.2.4 Tail.

B.3. Start time of each block

Given the Absolute time of Point Cloud Data Packets as t0, the start time of each block (i.e., the time when the first firing starts) can be calculated.

Single return mode

Block Block 1 Block 2

Start time (s) t0 – 9.249 – 41.666 * 2 t0 – 9.249 – 41.666

Dual return mode

Block Block 1 & Block 2

Start time (s) t0 – 9.249 – 41.666

B.4. Laser firing time of each channel
Given the start time of Block m as T(m), m {1, 2}, the laser firing time of Channel n in Block m is: t(m, n) = T(m) + t(n), n {1, 2, …, 128}.

-69-

Channel No. 1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81

t(n) 0
4144 12424 12376
0 4144 12424 12376 2504 9112 13280 14928 848 6616 10768 9112 848 4976 10768 6616 13280

Channel No. 2 6 10 14 18 22 26 30 34 38 42 46 50 54 58 62 66 70 74 78 82

t(n) 0
8240 4144 12376
0 0 8264 12424 4976 2504 13280 14928 6616 848 4976 10768 9112 848 10768 6616 13280

Channel No. 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 63 67 71 75 79 83

-70-

t(n) 8240
0 4112 8264 4112
0 4112 8264 6616 848 4976 10768 4976 2504 13280 14928 13280 2504 14928 9112 9112

Channel No. 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84

t(n) 4112
0 8264 12424 8240 4144 12376 848 6616 10768 9112 2504 9112 13280 13280 13280 2504 14928 4976 10768 4976

Channel No. 85 89 93 97 101 105 109 113 117 121 125

t(n) 2504 14928 4976 12424
0 4112 8264 4112
0 8264 8240

Channel No. 86 90 94 98 102 106 110 114 118 122 126

t(n) 2504 14928 9112
0 12424 4144 12376 4144
0 8240 12376

Channel No. 87 91 95 99 103 107 111 115 119 123 127

t(n) 848 10768 6616 4144
0 8240 12376
0 0 4144 12376

Channel No. 88 92 96 100 104 108 112 116 120 124 128

t(n) 10768 6616 4112
0 8264 8240 12424
0 12424 8264 8264

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Appendix C: Angle correction
Each lidar unit corresponds to an angle correction file, which contains the corrections of horizontal angles (azimuth) and vertical angles (elevation). Such corrections are used for: · Point cloud data analysis · Point cloud display in PandarView 2
Angle correction file
In case you need to obtain the file again, please do one of the following: · Send PTC command 0x05, as described in the TCP API Reference Manual (see Section 5 Communication protocol). · Export the file using PandarView 2 according to PandarView 2 user manual. · Contact sales representatives or technical support.

· The angle correction file is a .dat file. Please use a hex viewer/editor to check it. · Byte size of the file: 48 + 8 M + 368 N

C.1. Data Format

Unless otherwise specified, all the multi-byte fields are in little-endian format.

Field 0xEE 0xFF Protocol Version Major

Bytes 1 1 1

Type uint uint uint

Description SOP (start of packet) SOP (start of packet) Main class of the point cloud UDP packet structure Current value: 0x01

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Field Protocol Version Minor Channel Number Mirror Number Frame Number

Bytes 1 1 1 1

Type uint uint uint uint

Description
Subclass of the point cloud UDP packet structure Current value: 0x05
Channel number N 0x80 (128 channels)
Mirror number M 0x03 (3 mirror surfaces)
Frame number F for every 360° rotation Default: 0x03 (3 frames; each mirror surface corresponds to one frame)
This field is only used for PandarView 2 display configuration, not for point cloud data analysis.

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Field Frame Config Byte
Resolution Start_Frame [0: M-1]

Bytes 8
1 4 * M

Type uint
uint uint32 array

Description
Each byte (as a bitmap) corresponds to one frame, showing whether the measurements from each mirror surface are output to that frame. Only the first F frames are valid.
This field is only used for PandarView 2 display configuration, not for point cloud data analysis.
For example:
· When F = 3 and the first 3 bytes are 0000 0001, 0000 0010, and 0000 0100, the measurements from Mirror Surfaces 0/1/2 are output to Frames 0/1/2, respectively. That is, the frames are not stitched.
· When F = 1 and the first byte is 0000 0111, the measurements from Mirror Surfaces 0/1/2 are output to one frame. That is, three frames are stitched as one. The frame rate is 1/3 of that in the previous case, while the data points per frame are three times that of the previous case.
· When F = 1 and the first byte is 0000 0000, the measurements from Mirror Surfaces 0/1/2 are output to one frame according to their encoder angles in Point Cloud Data Packets. No angle correction is performed.
Used in the units of the fields below. Every 0x01 stands for 1°. For example: 0x01 stands for 1° and 0x02 stands for 2°.
The encoder angle of each mirror surface’s starting side Unit: Resolution / 25 600

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Field End_Frame [0: M-1] Azimuth_Offset [0: N-1] Elevation [0: N-1] Azimuth_Adjust [0: 23040-1]

Bytes 4 * M

Type uint32 array

4 * N

int32 array

4 * N

int32 array

23040 (N * 180) int8 array

Description
The encoder angle of each mirror surface’s ending side Unit: Resolution / 25 600

· The range of each mirror surface (End_Frame – Start_Frame) 120°
· One mirror surface’s End_Frame is exactly the next mirror surface’s Start_Frame, and so on.
· Sum of the three mirror surface ranges = 360°

Each channel’s horizontal angle offset, irrelevant to mirror rotation Unit: Resolution / 25 600
Each channel’s vertical angle offset, irrelevant to mirror rotation Unit: Resolution / 25 600
Each channel’s horizontal angle adjustments for every 2° encoder angle, relevant to mirror rotation

Format: 2D array [128][180] · The 180 columns correspond to encoder angle positions 0°, 2°, 4°, … …, and 358°.
· The 128 rows correspond to Channels 1 to 128.
Unit: Resolution * 0.01

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Field Elevation_Adjust [0: 23040-1]

Bytes 23040 (N * 180)

Type int8 array

SHA-256 Value

32

uint

Description Each channel’s vertical angle adjustments for every 2°encoder angle, relevant to mirror rotation
Format: 2D array[128][180] · The 180 columns correspond to encoder angle positions 0°, 2°, 4°, …
…, and 358°. · The 128 rows correspond to Channels 1 to 128. Unit: Resolution

• 0.01 SHA-256 hash of this angle correction file

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C.2. Angle correction calculation
C.2.1. Horizontal angle of the current firing channel

Encoder angle of each mirror surface’s starting side (start_frame)

In the angle correction file

Each channel’s horizontal angle offset (offset)

In the angle correction file

Each channel’s horizontal angle adjustments for every 2° encoder angle(adjust)

In the angle correction file

Unit: (resolution)

In the angle correction file

Encoder angle of the current firing channel (low-resolution part and high- resolution part fine) In the Body of Point Cloud Data Packets

C.2.2. Vertical angle of the current firing channel

Each channel’s vertical angle () Each channel’s vertical angle adjustments for every 2° encoder angle (adjust)

In the angle correction file In the angle correction file

If the encoder angle () is not divisible by 2°, the horizontal angle adjustments (adjust) and vertical angle adjustments (adjust) should be linearly
interpolated. For example: · If the adjust for 50° and 52° encoder angles are a and b, respectively, then at the 51° encoder angle position, adjust = (a + b) / 2. · If the adjust for 50° and 52° encoder angles are c and d, respectively, then at the 50.5° encoder angle position, adjust = (3c + d) / 4.

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Appendix D: Legal notice
Copyright © 2017-2023 Hesai Technology Co., Ltd. All rights reserved. Use or reproduction of this manual in parts or its entirety without the authorization of Hesai is prohibited. Hesai Technology makes no representations or warranties, either expressed or implied, with respect to the contents hereof and specifically disclaims any warranties, merchantability, or fitness for any particular purpose. Further, Hesai Technology reserves the right to revise this publication and to make changes from time to time in the contents hereof without obligation to notify any person of such revisions or changes. HESAI and HESAI logo are registered trademarks of Hesai Technology. All other trademarks, service marks, and company names in this manual or on Hesai’s official website are properties of their respective owners. The software included in this product contains the copyright that is registered under Hesai Technology. Any third party is not permitted, except as expressly permitted by the licensor or expressly required by applicable law, to decompile, reverse engineer, disassemble, modify, rent, lease, loan, distribute, sublicense, create derivative works based on the whole or any part of the software. Hesai Product Warranty Service Manual is on the Warranty Policy page of Hesai’s official website: https://www.hesaitech.com/warranty-policy/
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Hesai Technology Co., Ltd.
Phone: +86 400 805 1233 Website: www.hesaitech.com Address: Building L2, Hongqiao World Centre, Shanghai, China

Business Email: info@hesaitech.com Service Email: service@hesaitech.com

References

• Global Leader in LiDAR Sensor Solutions | HESAI Technology
• GitHub: Let’s build from here · GitHub
• HesaiTechnology · GitHub
• Product Software Downloads | HESAI Technology
• Product Software Downloads | HESAI Technology
• Technical Support | HESAI Technology
• Warranty Policy | HESAI Technology

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