RoboSense Helios16 LiDAR User Guide

RoboSense Helios16 LiDAR user guide: 16-channel 3D LiDAR with 150m range, 360°×30° FOV, MSOP/DIFOP protocols, GPS/PTP time sync, Web UI setup, and troubleshooting.

RoboSense Helios Series LiDAR

RoboSense Helios-Series High-Perf LiDAR: Customizable FoV, ≤0.2m near-blind zone, high-performance, low-power.For humanoids, drones, and AGV/AMR platforms.

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1. Product Description

1.1 Product Overview

Helios 16 is RoboSense's brand-new, high-precision 3D LiDAR system with a modular architecture design, featuring 16 laser beams. It is primarily used in applications such as robot environment perception, autonomous driving vehicle environment perception, V2X (Vehicle-to-Everything) communication, smart cities, and more.

Helios 16 offers a 30° (from-15° to +15°) vertical field of view with a uniform 2° vertical angular resolution. The data transmission protocol is Ethernet-based for in-vehicle use, supporting various time synchronization methods such as GPS, PTP, and gPTP. Additionally, Helios 16 is equipped with advanced features, including resistance to interference from multiple LiDAR and ambient light, the capability to operate in extreme temperatures as low as-40℃, compliance with vibration requirements for commercial vehicles, and the ability to function reliably in complex and demanding environments.

1.2 Product Structure

The structure of Helios 16 is illustrated in Figure 1 .

It mainly includes the following components:

1. Protective Cover Both the emitted laser and returned laser need to pass through the specially designed arc-shaped protective cover. Therefore, any obstruction within the laser's field of view (FOV) is strictly prohibited.
2. Aviation Connector The main body of the LiDAR is connected to the interface box using an aviation connector, which facilitates power supply and data transmission.
3. Mounting Holes Used to support and fix the position and orientation between the LiDAR and the bracket, it enhances installation efficiency and accuracy.
4. M3 Screw Mounting Holes Used to secure the LiDAR to the mounting bracket with M3 screws.

1.3 FOV Distribution

The FOV distribution of Helios 16 is presented in Table 1.

Table 1: Helios 16 FOV

The 16 laser beams are defined as 16 channels, and their corresponding vertical angles are shown in Figure 2 .

1.4 Specifications

Table 2: Helios 16 Specifications

1.5 Product Principle

1.5.1 Coordinate Mapping

As the LiDAR data packet contains only horizontal rotation angles and distance parameters, to present a three-dimensional point cloud, the polar coordinates (angle and distance) are transformed into Cartesian coordinates (x, y, z) according to the following equations:

$x = r*cos(w) * sin(α) + R*cos(α)$

$y = r*cos(w) * cos(α) + R*sin(α)$

$z = r*sin(w)$

where r is the measured distance, ω is the laser's vertical angle, α is the laser's horizontal rotation angle, R is the plane radius from the optical center to the origin, and x, y, z are the coordinates projected onto the Cartesian X, Y, Z axes.

1.5.2 Reflectivity Interpretation

Helios 16 provides reflectivity information to characterize the reflectance of measured objects. In Helios 16 data, the calibrated reflectivity range is from 1 to 255.

1.5.3 Return Modes

1.5.3.1 Return Modes Principle

Helios 16 supports multiple return modes, including Strongest Return, Last Return, First Return, and Dual Return modes. In the Dual Return mode, detailed information of the target object is displayed, and the data volume is twice that of the Single Return mode.

Helios 16 analyzes multiple return values received and outputs the strongest, last, or first return value based on user selection, or outputs dual return values. In the Strongest Return mode, only the strongest reflected return value is output; in the Last Return mode, only the last detected return in the time domain is output.

1.5.3.2 Return Mode Flags

By default, Helios 16 is set to the Strongest Return mode. If the user needs to change the settings, please refer to Appendix A.2 in the product parameter setting for configuration. In DIFOP, the 300th byte represents the flag for the return mode, as shown in Table 3:

Table 3: Return Mode and Flags Mapping

1.5.4 Phase Locking

Helios 16's phase locking function allows the device to emit lasers at specific angles when the sensor reaches a whole second. Figure 4 illustrates Helios 16's setup with different phase angles. The red arrows indicate that at the whole second, the sensor rotates to 0°, 135°, and 270° to emit lasers. Refer to Figure 13 for the coordinate system details.

The "Phase Lock" parameter setting is available in the Web interface under Setting >Phase Lock Setting. It allows users to set the locked phase angle, which should be an integer ranging from 0 to 359. For more details, refer to section 4.2 of the product manual.

1.5.5 Time Synchronization Mode

Helios 16 supports three time synchronization methods: GPS + PPS, PTP (IEEE 1588 V2 protocol), and gPTP (IEEE 802.1 AS protocol). Users can configure these settings through the Web interface. For more details, refer to section 4.2 of the product manual.

1.5.5.1 GPS Time Synchronization Principle

The GPS module continuously sends GPRMC data and PPS synchronization pulse signals to the product. The PPS synchronization pulse length should be between 20 to 200 ms, and the GPRMC data must be completed within 500 ms of the synchronization pulse. The timing diagram is shown in Figure 5 .

1.5.5.2 GPS Time Synchronization Usage

The GPS_REC interface of Helios 16 LiDAR adopts the RS232 electrical level protocol. Refer to Table 4 for the pin definition.

Table 4: Product Time Synchronization Pin Definitions

The external GPS module needs to set the output serial port baud rate to 9600 bps, 8 data bits, no parity bit, and 1 stop bit. Helios 16 only reads GPRMC-formatted data sent by the GPS module. The standard format is as follows:

$ GPRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12> * hh

<1> UTC time <2> Positioning status: A = valid positioning, V = invalid positioning <3> Latitude <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 *

1.5.5.3 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.

1.5.5.4 gPTP Synchronization Principle

gPTP(general Precise Time Protocol, IEEE 802.1AS protocol) is a derivative protocol of PTP in Time-Sensitive Networking (TSN). The synchronization mechanism uses the same P2P peer delay mechanism as the PTP protocol and adopts Ethernet L2 layer communication. Unlike PTP, gPTP requires the use of hardware-based timestamps, i.e., hardware timestamps, so the requirements for switches and master clocks are more stringent, complying with the IEEE 802.1AS protocol.

1.5.5.5 PTP/gPTP Wiring Method

To use PTP/gPTP synchronization, the following preparations are required. Refer to section 2.4 of the product manual for connection details:

1. Select PTP/gPTP mode in the Web interface. See section 3.2 of the product manual for details.
2. PTP Master/gPTP Master time source (plug and play, no additional configuration required).
3. Ethernet switch.
4. Devices that support PTP/gPTP protocols and need time synchronization.

2. Product Installation

2.1 Accessory Description

The standard accessories included with Helios 16 LiDAR are listed in Table 5 for reference.

Table 5: Standard Accessory List

2.2 Mechanical Installation

The structural installation diagram of the LiDAR is shown in Figure 6 .

1. Screw Specifications:
1. GB/T70.1, M3 × 12, internal hexagon socket head, strength grade 10.9, with an anti-drop.
2. GB/T70.1, M3 × 8, internal hexagon socket head, strength grade 10.9, with anti-drop.
2. Installation Requirements:
1. The installation surface should have a flatness better than 0.2 mm.
2. Use 3 M3 screws for mounting on the bottom surface, with a mounting depth of 4 ~ 5 mm,and recommended tightening torque of 13 ± 1 kgf.cm.
3. Use 2 Φ4 locating pins on the bottom surface for positioning, ensuring they do not protrude more than 4 mm.
4. The tilt angle during installation should not exceed 15°.
5. When installing the LiDAR and both the top and bottom surfaces have contact surfaces, ensure that the distance between the contact surfaces is greater than the height of the LiDAR to avoid squeezing the LiDAR.
6. When routing the wires during installation, do not make the cables too tight (leave at least 2 cm of installation allowance) to ensure that the cables have some slack.

3. Bracket Stiffness and Strength Requirements:
1. The fixed bracket should have good rigidity to securely mount and maintain the LiDAR in a stable state under various conditions. Therefore, the first-order modal frequency of the LiDAR and its fixed bracket should be at least greater than 50 Hz.
2. The LiDAR will undergo various random vibrations, mechanical impacts, etc., during use. The bracket must withstand significant loads, so it requires sufficient strength. It is recommended to use aluminum alloy (thickness ≥ 4 mm) or galvanized steel plate (thickness ≥ 2 mm) for the bracket material. Reinforcements should be added in various directions to increase stiffness and strength, and it is advised to avoid designing structures with sharp angles or notches less than 0.3 mm to prevent stress concentration. The strength of the bracket needs to be verified through simulation.
4. Heat Dissipation Requirements:
1. The bracket material should be made of materials with a thermal conductivity greater than 50 W/m·K, such as aluminum alloy or galvanized steel plate. Heat fins should be added to the bracket, and the spacing, height, and direction of the fins should be designed reasonably to increase the heat dissipation area. The direction of the fins should align with the direction of air convection for more effective heat dissipation.
2. Ensure that the LiDAR base or top cover is not covered by non-metallic materials to avoid affecting the overall heat dissipation and causing excessive temperature rise of the LiDAR.

2.3 Interface Description

2.3.1 Aviation Plug Interface and Definitions

The Helios 16 LiDAR has a bottom-mounted aviation plug, as shown in Figure 8 .

For detailed pin definitions of the aviation plug interface, please refer to Table 6

Table 6: Pin Definitions of the Aviation Plug Interface

2.3.2 Interface Box

The Helios 16 accessory interface box is equipped with status indicator lights and various interfaces, as shown in Figure 9 . It can be connected to power input, RJ45 Ethernet port, and GPS input cable (the cable length for the aviation plug version of the interface box is 3 meters; for other cable length requirements, please contact Robosense).

The details of each interface definition and specifications are provided in Table 7.

Table 7: Interface Box Interface Specifications

2.3.3 Power Interface

The Helios 16 power interface uses a standard DC 5.5- 2.1 interface.

When the Interface Box is working normally, the red input and green output indicator lights will be lit. If the external power input is normal, but the indicator lights on the Interface Box are not lit, the Interface Box may be damaged. In this case, please contact Robosense.

2.3.4 RJ45 Ethernet Port

The Helios 16 Ethernet interface follows the EIA/TIA568B standard.

2.3.4.1 GPS Sync Interface

The Helios 16 sync interface is defined as follows: GPS REC is for GPS UART input, and GPS PULSE is for GPS PPS input. The pin positions of the Interface Box sync interface are shown in Figure 10 .

For the detailed interface definitions, please refer to Table 8.

Table 8: Sync Interface Definitions

3.4 Quick Connection

The Helios 16 network parameters can be configured, and the default factory setting uses fixed IP and port number mode, as shown in Table 9.

Table 9: Default Factory Network Configuration Table

When using the product, the user needs to set the computer's IP address to be in the same subnet as the product, for example, 192.168.1.x (where x can be any value between 1 and 254), and the subnet mask is 255.255.255.0. For unknown product network configuration information, please connect the product and use Wireshark to capture the output package of the product for analysis. The IP configuration and connection methods are as follows:

1. Connecting the LiDAR

The connection method is shown in Figure 11.

1. Connect the LiDAR and Interface Box using the aviation plug.
2. Connect the PC and Interface Box using the RJ45 Ethernet port.
3. After powering on, under normal working conditions, the red and green power indicator lights on the LiDAR's Interface Box will be constantly on. The positions of the indicator lights are shown in Figure 9 .

1. Through the ".pcap" packets captured by Wireshark software, get the Local IP of Computer by analyzing " arp" packets
1. Perform the following steps after the LiDAR and PC are connected:
2. Start Wireshark (a third-party network analysis tool) and select the correct network interface to begin capturing packet.
3. Use the search box in Wireshark and enter "arp" to search for the mutual addressing packets between the LiDAR and PC, as shown in Figure 12.

4. In Figure 12 , the "SutengIn" in the Source column indicates the source information of the LiDAR, indicating that the Source IP is 192.168.1.200, which is the LiDAR's IP. The request is accessing 192.168.1.102, which is the PC's IP. If the local IP is not the requested access IP, then configure the PC's local IP as 192.168.1.102 as shown in step 3. If the access is successful, proceed to step 4.
2. Configuring the PC's Local IP
1. In the Control Panel, go to "Network and Internet" and then "Network and Sharing Center." In the "View your active networks" section, click on the corresponding Ethernet connection to enter the corresponding "Ethernet Status," and then click on "Properties."
2. Double-click "Internet Protocol Version 4 (TCP/IPv4)" to enter the IP information settings and use a static IP for configuration.
3. Set the local IP address to 192.168.1.102, subnet mask to 255.255.255.0, and click "OK" to complete the PC's static IP setting.
3. Connection Completed

3. Product Usage

3.1 Product Coordinate System

The coordinates and rotation direction of the product are shown in Figure 13 .

3.2 Web UI Usage

3.2.1 Web UI Functions

Helios 16 only supports parameter setting, viewing of operational information/status, and firmware upgrades through the web interface.

The Helios 16 web address changes according to the Device IP. The default Device IP is 192.168.1.200. If you have changed the Device IP, the web address will be the newly set IP.

3.2.2 Accessing the Web UI Interface

Once the product is connected and correctly configured as required, use a computer browser to access the product's IP address (default Device IP: 192.168.1.200) to enter the Helios 16 web homepage. The default page is the "Device" tab.

3.2.3 Using the Web UI Interface

For detailed instructions on using the Web UI interface, please refer to Appendix A of the product manual.

3.3 RSView Usage

For data visualization with Helios 16, you can use free tools such as Wireshark and tcp-dump to obtain raw data. RSView can provide a more convenient way to visualize the raw data.

3.3.1 Software Functions

RSView enables real-time visualization of Helios 16 data. It can also replay data saved in ".pcap" file format, but does not support ".pcapng" files at the moment.

In RSView, the distance measurement values obtained by Helios 16 are displayed as points. It supports various custom colors to display data, such as reflection intensity, time, distance, horizontal angle, and laser beam index. The displayed data can be exported and saved in ".csv" format, and RSView version 3.1.3 and later versions support exporting data in ".las" format.

RSView includes the following features:

1. Real-time display of data via Ethernet.
2. Save real-time data as PCAPfiles.
3. Replay data from recorded PCAPfiles.
4. Various visualization modes, such as distance, time, horizontal angle, etc.
5. Display point data in tabular format.
6. Export point cloud data as CSV files.
7. Distance measurement tool.
8. Display multiple frames of replayed data simultaneously.
9. Showor hide individual laser beams from Helios 16.
10. Clipping display.

3.3.2 Installing RSView

RSView can be run on Windows 64-bit and Ubuntu 18.04 or higher operating systems. You can download the latest version of RSView software compressed package from the Robosense official website (http://www.robosense.cn/resources). After downloading, make sure the extraction path does not contain Chinese characters. The software does not require installation; simply run the executable file after extraction to use it.

3.3.3 Using RSView

After opening RSView, you can access the user guide by pressing the F1 button or by clicking on the "RS-LiDAR User Guide" option in the Help menu.

3.4 Communication Protocols

Helios 16 communicates with a computer via Ethernet using UDP (User Datagram Protocol). The communication protocols between Helios 16 and the computer fall into two categories, as described in Table 10.

Table 10: Protocol Overview

3.4.1 MSOP and DIFOP Data Protocols

The UDP packets sent by Helios 16 have a payload of 1248 bytes. The data structure for the Main Data Stream Output Protocol (MSOP) and Device Information Output Protocol (DIFOP) is shown in Figure 14 .

3.4.2 Main Data Stream Output Protocol (MSOP)

Main Data Stream Output Protocol, abbreviated as MSOP, is used for product output and computer parsing. The default port number is 6699.

3.4.2.1 Header

The header consists of 42 bytes and is used to identify the start of the data. The data structure details are shown in Table 11.

Table 11: MSOP Header Data Table

3.4.2.2 Data Block Interval

As shown in Table 12, the Data Block interval is the measurement part of the MSOP (Measurement Data Stream Output) packet from the sensor, and it consists of a total of 1200 bytes. The Data Block is composed of 12 individual blocks, each with a length of 100 bytes, representing a complete set of ranging data.

Within each 100-byte Data Block, the space is structured as follows:2 bytes for the flag, represented by the value 0xffee.2 bytes for the Azimuth, which indicates the horizontal rotation angle information. Each azimuth angle corresponds to 16 channels of data, containing one complete set of information for 16 channels. (The relationship between channel numbers and vertical angles can be found in the product manual's Appendix D).

Table 12: Data Block Packet Definition

1. Channel Data Definition

The channel data, Channel data, is represented by 3 bytes. The high two bytes represent the distance information, and the low byte represents the reflectivity information, as shown in Table 13.

Table 13: Channel Data Representation

Red box: Header ID

Yellow box: Data Block flag

Blue box:Azimuth value for Channel data 1

Green box: Distance value for Channel data 1

2. Angle Value Definition: In each data block of the Helios 16 series, the output angle value corresponds to the angle of the first channel's laser ranging in that block. The angle value is obtained from the angle encoder, where the encoder's zero position represents the zero point of the angle. The resolution of the horizontal rotation angle value is 0.01°. Each data block contains 32 sets of channel data, representing two sets of laser ranging information for 16 channels each. However, each data block only has one horizontal rotation angle value. Therefore, in the single return mode, the horizontal rotation angle value for each data block corresponds to the horizontal angle of the first channel in the first set of 16-channel ranging in that data block. The horizontal angle of the first channel in the second set of 16 channels can be obtained through interpolation during the point cloud parsing process to calculate the new angle.
3. Angle Interpolation Calculation Method

The Helios 16 outputs the horizontal rotation angle information only once every set of 16-channel laser ranging. Therefore, in the single return mode, interpolation is required to obtain the angle for the set of 16-channel laser ranging where no horizontal rotation angle information is output. There are various interpolation methods available, and the following method is the simplest and most direct.

For a set of data in a packet, the time interval between the first data of Block 1 and the first data of Block 2 is ~100us, and during this period, the radar can be assumed to rotate at a constant speed. Therefore, we can calculate that the horizontal angle of the first data for the N+1 set of 16-channel laser ranging is the average of the horizontal angles of the first data for the N set of 16-channel laser ranging and the N+2 set of 16-channel laser ranging. The following is pseudocode, which checks if the horizontal rotation angle goes from 359.99 to 0 degrees between the N-th set and N+2-th set. For this example, let N = 1:

// First, adjust for a rollover from 359.99° to 0°
If (Azimuth[3] < Azimuth[1])
Then Azimuth[3]:= Azimuth[3]+360;
End if;
// Perform the interpolation
If (Azimuth[2]>360)
Azimuth[2]:=Azimuth[1]+((Azimuth[3]-Azimuth[1])/2);
// Correct for any rollover over from 359.99° to 0°
Then Azimuth[2]:= Azimuth[2]-360;
End if

3.4.2.3 Tail

The tail consists of 6 bytes, with 4 bytes reserved information and 2 bytes of 0x00, 0xFF.

3.4.3 Device Info Output Protocol (DIFOP)

Device Info Output Protocol, abbreviated as DIFOP, is used for product output and computer reading. The default port number is 7788.

DIFOP is an "output-only" protocol used to periodically send information such as product serial number (S/N), firmware version, computer driver compatibility information, configuration information, angle information, running status, fault diagnosis, etc., to users. Users can read DIFOP to interpret specific information about the currently used product.

A complete DIFOP packet has a data format structure of synchronization header, data area, and tail. Each data packet consists of 8 bytes of synchronization header, 1238 bytes of data area (Data), and 2 bytes of tail. The basic structure of the data packet is shown in Table 14.

Table 14: Data Format Structure of DIFOP Packet

4. Product Maintenance

4.1 Transportation and Logistics

4.2 Storage

4.3 Product Cleaning

To ensure accurate perception of the surrounding environment, keep the RS-LiDAR's circular protective cover clean.

4.3.1 Precautions

4.3.2 Required Materials

1. Clean and dust-free cloth;
2. Neutral solution at moderate temperature (such as soapy water, distilled water, 99% concentration of ethanol, etc.).

4.3.3 Cleaning Method

1. If the LiDAR surface is only covered with some dust:
1. Use a clean and dust-free cloth, dip it in a small amount of neutral solution;
2. Gently wipe the LiDAR surface;
3. Dry it with a clean and dry dust-free cloth.
2. If the LiDAR surface is covered with mud or other solid foreign objects:
1. First, spray clean water on the dirty part of the LiDAR surface to remove the mud or foreign objects (Note: Do not directly wipe off the mud with a dust-free cloth, as it may scratch the surface, especially the protective cover);
2. Then spray warm soapy water on the dirty part. The lubricating effect of the soapy water helps to remove the foreign objects. Gently wipe the LiDAR surface with a fiber cloth, but be careful not to scratch the surface;
3. Finally, rinse off the residual soap on the LiDAR surface with clean water (if there is still residue, clean it again with 99% ethanol) and dry it with a clean and dry dust-free cloth.

5. Fault Diagnosis

This chapter lists some common problems encountered during the use of the product and their corresponding troubleshooting methods. For details,refer to Table 15.

Table 15: Common Fault Troubleshooting Methods

6 After-sales Service

If the solutions provided in Chapter 6 of the troubleshooting guide do not solve the problem, please promptly contact RoboSense.

Official Website: https://www.robosense.cn/contact

Email: support@robosense.cn

Phone: 0755-86325830 / 15338772453

Appendix A Web UI Operation

A.1 Product Information

The web interface of the LiDAR provides the default product information page, as shown in Figure 16 :

1. Top Board: Mainboard firmware version.
2. Bottom Board: Baseboard firmware version.
3. Software Version: Software version.
4. Motor Firmware Version: Motor version.
5. S/N: Product serial number.
6. Mac Address: MAC address.
7. Model: Product name.

A.2 Product Parameter Settings

The "Setting" tab on the web page is the LiDAR parameter setting page where you can change Device IP, Port number, Return mode, Rotation speed, and Angle trigger settings. The illustrations and descriptions are shown in Figure 17 and Figure 18 :

1. Support unicast (default) / broadcast mode. Set the Destination IP to 255.255.255.255 for broadcast mode. The default factory setting is 192.168.1.102.
2. The data ports for MSOP and DIFOP can be changed, with a value range of 1025 to 65535.
3. Dropdown options for "Return Mode" include strongest (default) / last / first / dual return modes.
4. FOV (Field of View) can be set within the angle range of 0 to 360 degrees. Once set, only point cloud data within the specified FOV will be output.
5. The designated rotation speed can be set to 300 rpm, 600 rpm (default), or 1200 rpm.
6. Dropdown options for "Time Synchronization Source" include GPS, PTP-P2P, PTP-E2E-L4, PTP-E2E-L2, and PTP-gPTP to determine the time synchronization method.
7. Dropdown options for "Operation Mode" include Standby / High Performance (default) modes. In Standby mode, the LiDAR motor and transmitter stop working.
8. Dropdown options for "Reflectivity Enhance" offer different reflectivity mapping modes. "OFF" represents the original reflectivity mode, while "On" enables lane enhancement mode to improve lane distinction.

1. Angle Pulse Setting: Configure angle-triggering function in this section. The angle-triggering function is turned off by default.
2. Trigger Mode: There are two starting angle modes. Mode 1 increases the starting pulse width by 25% (default), and Mode 2 keeps the starting pulse width unchanged.
3. Group Switch: Enable/Disable "Pulse Trigger Switch." When "All On" is checked, all SYNC trigger settings are enabled. The default is "All Off."
4. Group: This section corresponds to SYNC OUT groups. Helios 16 contains SYNC OUT1 & SYNC OUT2,but the power box only connects to SYNC OUT1. Refer to Table 8 for specific definitions.
5. Pulse Trigger Switch: Enable/Disable the triggering function. When Pulse Trigger Switch is checked "ON," the options become editable; when unchecked, they are grayed out and not editable.
6. Pulse Start Angle: Set the corresponding starting angle, with a default value of 0°.Input values format must be integer.
7. Pulse Width: Set the corresponding pulse width, with a default value of 10 ms. Input values must be multiples of 20 ns, and the duty cycle can go up to a maximum of 50%.
8. Pulse Step: Set the corresponding pulse step, the default value format must be floating with resolution of 0.1 degree.

A.3 Product Diagnostics / Operating Status

This page allows real-time monitoring of the LiDAR's operating status, including voltage, current, real-time speed, runtime, temperature, and other information, as shown in Figure 19 :

1. Voltage Monitor: Monitors the product's voltage. When the product is in Standby mode, this section will be highlighted in red.
2. User can view the current operating temperature of the product.
3. User can check the RPM (Rotations Per Minute) to get real-time information about the current rotational speed of the product.
4. Laser Status: The laser can be set to either "On" (default) or "Off." When the product is set to Standby mode, it will be set to "Off."
5. User can view the Start-up Times to get the total number of times the product has been started. The count increases by one each time the power is cycled and the product restarts.
6. User can check the Elapsed time Total T0 to get the overall running time of the product and the accumulated working time of the product at various temperatures.

A.4 Product Firmware Upgrade

Click on the "System" on the web page. This page allows the firmware upgrade for the mainboard, baseboard, software, web interface, and motor. Follow the steps below:

1. Contact RoboSense to obtain the upgrade firmware. Once the firmware is ready, click "Choose File," as shown in Figure 20 .

2. Select the folder containing the corresponding firmware for the upgrade, then click "Open" (avoid using Chinese characters in the file path), as shown in Figure 21 .

3. After selecting the firmware for upgrade, the filename will change to the selected firmware name, indicating that it is successfully loaded, as shown in Figure 22 . Click "Update" to proceed with the upgrade.

4. After successfully updating the firmware, the web page will display a success message, and the product will automatically restart. Once the restart is complete, you can log back in to the web page homepage to check if the firmware version has been upgraded successfully, as shown in Figure 23 .

Appendix B ROS & ROS2 Package

rslidar_sdk is the ROS-based driver SDK. You can download it from the RoboSense GitHub repository or contact RoboSense for access.

1. rslidar_sdk depends on rs_driver, which is the basic RoboSense driver. Download rs_driver from the GitHub platform.
2. If you are using ROS2, rslidar_sdk also depends on rslidar_msg, which defines the message format. Download the msg file from the GitHub platform.
3. The SDK package contains comprehensive usage guidelines. Before using the driver SDK, please read the README file and documentation under the doc folder.

Appendix C Register Definitions

This appendix provides additional information to section 3.4, defining the various registers in the protocol. All calculations are in big-endian format. The "Value" represents the decimal value obtained after converting the offset bytes.

C.1 Motor Speed (MOT_SPD) Register

Table 16: Motor Speed Register

C.2 Ethernet (ETH) Register

Table 17: Ethernet Register

C.3 FOV Setting (FOV_SET) Register

Table 18: FOV Setting Register

C.4 Motor Phase (MOT_PHASE) Register

Table 19: Motor Phase Register

C.5 Main Board Firmware Version (TOP_FRM)

Table 20: Main Board Firmware Version

C.6 Bottom Board Firmware Version (BOT_FRM)

Table 21: Bottom Board Firmware Version

C.7 APP Software Version (SOF_FRM)

Table 22: Software Version

C.8 Motor Firmware Version (MOT_FRM)

Table 23: Motor Firmware Version

C.9 Serial Number (SN)

Table 24: Serial Number Register

C.10 Time Synchronization Information (TIME_SYNC_INF)

Table 25: Time Synchronization Information Register

C.11 Time (UTC_TIME)

Table 26: Time Register

C.12 Operating Status (STATUS)

Table 27: Operating Status Register

C.13 Fault Diagnosis (FAULT_DIGS)

Table 28: Fault Diagnosis Register

Table 29: GPS Signal Input Status Register (GPS_ST)

C.14 GPRMC Data Packet-ASCII Code Data

The GPRMC data packet reserves 86 bytes to store the received GPRMC message, which is output from the external GPS module. The data can be parsed and viewed in ASCII code.

C.15 Vertical Angle Calibration (COR_VERT_ANG)

Table 30: Vertical Angle Calibration Register

C.16 Horizontal Angle Calibration (COR_HOR_ANG)

Table 31: Horizontal Angle Calibration Register

Appendix D Accurate Point Time Calculation

In each MSOP Packet, there are 12 Blocks, and each Block contains two complete sets of 16-channel laser data.Therefore, one Packet consists of 12 complete sets of laser data. It takes 55.56 microseconds for all 16 channels to complete one round of transmission and charging.

Helios 16 has added anti-interference measures,so the emission timing is not regular. For the time calculation of single return and double return points, please refer to Table 32 and Table 33.

Table 32: Time Offset of Each Single Return Laser Point in MSOP Packet (us)

Table 33: Time Offset of Each Dual Return Laser Point in MSOP Packet (us)

Appendix E Channel Capability Range Chart for Various Models

Table 34: Helios 16 - Channel Capability Range Chart

Appendix F Channel Ranging Capability Table

Table 35: Channel Ranging Capability