1.3.1.1. Livox LiDAR Communication Protocol–Avia2

Release History
Date	Version	Description
20260730	v1.0	1. Initialized version

1.3.1.2. Overview

This communication protocol is only used for livox Avia2 LiDAR.

1.3.1.2.1. Protocol Types

There are two types of data protocols between the user and the LiDAR, see as below:

Point cloud data protocol:

Point cloud data sampled and output by the LiDAR;
Internal IMU data of the LiDAR.

For details, see (Data Types).

Control command protocol:

Configure and query LiDAR parameters; LiDAR reset;
Push and query LiDAR status;
Upgrade related;

For details, see (CMD Details).

Both protocols are encapsulated using UDP data segments, and the protocol data is Little-endian.

1.3.1.2.2. LiDAR Working Status

The state machine of the current LiDAR is shown in the figure. The state enumeration values currently used by the LiDAR product are as follows:

LiDAR Status	Enumeration Value	Whether to Support User Settings
SAMPLING	0x01	Support(By Parameter Configuration)
IDLE	0x02	Support(By Parameter Configuration)
ERROR	0x04	Not Support
SELFCHECK	0x05	Not Support
MOTORSTARUP	0x06	Not Support
READY	0x09	Support(By Parameter Configuration)

1.3.1.2.3. Port Description

The source port and destination port are explained as follows according to the different data types:

Data Type	Transmission Direction	LiDAR Port	Host Computer Port	Transmission Type	Transmission Protocol
Device Type Query	LiDAR <—-> PC	56000	Any	Broadcast	UDP

56000 is used as the fixed listening port of Livox LiDAR, mainly used for the host computer to query the device through broadcast:

1. Only the device type query command (cmd_id: 0x0000) is supported. The host computer obtains the specific device type of the LiDAR through this port. This command response is replied by broadcast, so that when the host computer and the LiDAR IP are not in the same network segment, the host computer can still identify the LiDAR.

Avia2 Communication Port:

Data Type	Transmission Direction	LiDAR Port	Host Computer Port	Transmission Type	Transmission Protocol
Control Command	LiDAR<—> Host Computer	56100	Any (56101 recommended)	Unicast	UDP
Push Command	LiDAR —> Host Computer	56200	Configurable (default 56201)	Default Unicast	UDP
Point Cloud Data	LiDAR —> Host Computer	56300	Configurable (default 56301)	Default Unicast(Support Multicast)	UDP
IMU Data	LiDAR —> Host Computer	56400	Configurable (default 56401)	Default Unicast(Support Multicast)	UDP
LOG Data	LiDAR <—> Host Computer	56500	Any (56501 recommended)	Unicast	UDP

1.3.1.3. Point Cloud & IMU Data Protocol

1.3.1.3.1. Protocol Format

Point cloud data format output by the LiDAR:

Field	Offset (bytes)	Size (bytes)	Description
version	0	1	Package protocol version: currently 1
length	1	2	The length of the entire UDP data segment starting from `version`
reserved	3	2	Reserved
dot_num	5	2	The current UDP packet data field contains the number of points
udp_cnt	7	2	Point cloud UDP packet count, each UDP packet is incremented by 1 in turn, and cleared to 0 at the beginning of the point cloud frame
frame_cnt	9	1	This field is not yet enabled
data_type	10	1	Data type. For details, see (Data Types)
time_type	11	1	Timestamp type. For details, see (Timestamp)
reserved1	12	12	Reserved
crc32	24	4	timestamp+data segment check code, using CRC-32 algorithm (see (CRC Algorithm) for details)
timestamp	28	8	Point cloud timestamp. For details, see (Timestamp)
data	36	–	Data information. For details, see (Data Types)

1.3.1.3.2. Timestamp

Points within every 100ms form a frame; data packets within this 100ms share the same timestamp.

Timestamp type:

Timestamp Type	Sync Source Type	Data Format	Description
0	No synchronization source, the timestamp is the time when the LiDAR is turned on	uint64_t	Unit: ns
1	gPTP/PTP synchronization, the time of master clock source as a timestamp	uint64_t	Unit: ns
2	GPS time synchronization	uint64_t	Unit: ns
5	NTP time synchronization	uint64_t	Unit: ns

Notice:

The time limit for GPS time synchronization is from 1/1/2000 to 31/12/2037
PTP time synchronization does not support IEEE1588v2.1
Not recommended for use in scenarios where IEEE1588v2.0 and gPTP coexist;

1.3.1.3.3. Data Types

There are N samples in each packet. The size of N depends on the data type.

There are 3 data types, the default point cloud data type is 1:

Data Type	Sampling Type	Echo Mode	Coordinate Mode
0	IMU data
1	Point cloud data	Single echo mode	Cartesian coordinates
17	Point cloud data	Dual echo mode	Cartesian coordinates

Data Type 0

IMU Data:

Field	Offset (bytes)	Data Type	Description
gyro_x	0	float	Unit: rad/s
gyro_y	4	float	Unit: rad/s
gyro_z	8	float	Unit: rad/s
acc_x	12	float	Unit: g
acc_y	16	float	Unit: g
acc_z	20	float	Unit: g

Data Type 1

Single echo Cartesian coordinate data format:

Field	Offset (bytes)	Data Type	Description
x	0	int32_t	X axis, Unit: mm
y	4	int32_t	Y axis, Unit: mm
z	8	int32_t	Z axis, Unit: mm
intensity	12	uint8_t	Reflectivity
tag	13	uint8_t	Currently not enabled

Data Type 17

Dual echo Cartesian coordinate data format:

Field	Offset (bytes)	Data Type	Description
x_1	0	int32_t	Echo 1 X axis, Unit: mm
y_1	4	int32_t	Echo 1 Y axis, Unit: mm
z_1	8	int32_t	Echo 1 Z axis, Unit: mm
intensity1	12	uint8_t	Reflectivity 1
tag1	13	uint8_t	Currently not enabled
x_2	14	int32_t	Echo 2 X axis, Unit: mm
y_2	18	int32_t	Echo 2 Y axis, Unit: mm
z_2	22	int32_t	Echo 2 Z axis, Unit: mm
intensity2	26	uint8_t	Reflectivity 2
tag2	27	uint8_t	Currently not enabled

1.3.1.4. Control Command

1.3.1.4.1. Frame Format

Format of control command is as follows:

Field	Offset(byte)	Size (byte)	Description
sof	0	1	Starting byte, fixed to be 0xAA
version	1	1	Protocol version, 0 for current version
length	2	2	Length of frame; The number of bytes from beginning of `sof` to end of entire `data` segment. Max value: 1400
seq_num	4	4	This field is incremented by 1 for each new REQ request message; This field of ACK message is the same as REQ and can be used for message matching
cmd_id	8	2	Different types of messages are distinguished by this field, For details, see (Command ID)
cmd_type	10	1	Command Type: 0x00: REQ, actively send data request; 0x01: ACK, response to REQ data
sender_type	11	1	The sender’s device type: 0 means the host computer sends the message, 1 means the LiDAR sends the message
resv	12	6	Reserved extension field, can be ignored
crc_16	18	2	Frame header checksum, check data is 18 bytes from `sof` to `crc_16` (not included), using CRC-16/CCITT-FALSE algorithm (see (CRC Algorithm) for details)
crc32	20	4	crc32 checksum: data field checksum, using CRC-32 algorithm (see (CRC Algorithm) for details) When length of data field is 0, CRC32 needs to be padded with 0.
data	24	n	See (CMD Details)

1.3.1.4.2. Command ID

LiDAR command id list:

Function Type	CMD ID	Function
Device Type Query	0x0000	Discovery by broadcasting
LiDAR Information	0x0100	Parameter information configuration
	0x0101	Inquire LiDAR information
	0x0102	Push LiDAR information
Control CMD	0x0200	Request reboot device
	0x0201	Restore factory settings
	0x0202	Set GPS timestamp
log CMD	0x0300	Log file push
	0x0301	Log collection configuration
	0x0302	Log system time synchronization
	0x0303	Debug raw data collection configuration
General Upgrade	0x0400	Request to start upgrade
	0x0401	Firmware data transfer
	0x0402	Firmware transfer complete
	0x0403	Get firmware upgrade status

1.3.1.4.3. Communication Process

Host computer communication process

1.3.1.5. CMD Details

1.3.1.5.1. Device Type Query

1.3.1.5.1.1. 0x0000 Discovery By Broadcasting

Request

CMD	Name	Offset(byte)	Data Type	Description
data	NULL

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)
	dev_type	1	uint8_t	LiDAR type
	serial_number	2	uint8_t[16]	LiDAR SN
	lidar_ip	18	uint8_t[4]	LiDAR IP address E.g: AA.BB.CC.DD user_ip[0] = AA user_ip[1] = BB user_ip[2] = CC user_ip[3] = DD
	cmd_port	22	uint16_t	Current control command port of the LiDAR

1.3.1.5.2. LiDAR Information

1.3.1.5.2.1. 0x0100 Parameter Configuration

Request

CMD	Name	Offset(byte)	Data Type	Description
data	key_num	0	uint16_t	Number of `key_value_list` entries to be configured
	rsvd	2	uint16_t
	key_value_list	4	key_value_list[N]	Key content list; For convenience of expansion, multiple pieces of information are placed in a variable-length key-value list

Format of each parameter in key_value_list is as follows:

Data Field	Offset(byte)	Data Type	Description
key	0	uint16_t	Key number, see the key table below
length	2	uint16_t	Length of value to the key
value	4	–	Value content to the key

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)
	error_key	1	uint16_t	The first LiDAR key that failed to be configured

1.3.1.5.2.2. 0x0101 Parameter Inquire

Request

CMD	Name	Offset(byte)	Data Type	Description
data	key_num	0	uint16_t	Number of entries in `key_list`
	rsvd	2	uint16_t
	key_list	4	–	Key number list

The key type in the key_list:

Data Field	Offset(byte)	Data Type	Description
key	0	uint16_t	key number

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)
	key_num	1	uint16_t	Number of `key_value_list` entries
	key_value_list	3	–	Information of keys queried successfully

1.3.1.5.2.3. 0x0102 LiDAR Information Push

LiDAR pushes actively

CMD	Name	Offset(byte)	Data Type	Description
data	key_num	0	uint16_t	Number of `key_value_list` entries
	rsvd	2	uint16_t
	key_value_list	4	–	info_list

Format of each parameter in key_value_list is as follows:

Data Field	Offset(byte)	Data Type	Description
key	0	uint16_t	Key number, see the key table below
length	2	uint16_t	Length of value to the key
value	4	–	Content of pushed key information

Specific meanings of key_value_list are as follows:

Number(key)	Name	Length	Type	Content	Support Parameter Information Configuration Command(cmd_id=0x0100)
0x0000	pcl_data_type	1	uint8_t	Type of point cloud data, see (Data Types): 0x01: Single echo Cartesian coordinate 0x11: Dual echo Cartesian coordinate	Yes
0x0004	lidar_ipcfg	12	uint8_t[12]	LiDAR IP address configuration LiDAR IP address: AA.BB.CC.DD data[0]: AA data[1]: BB data[2]: CC data[3]: DD LiDAR IPV4 subnet mask data[4~7] LiDAR IPV4 gateway data[8~11]	Yes
0x0005	state_info_host_ipcfg	8	uint8_t[8]	IP address configuration for pushing LiDAR status information data[0~3] Destination IP address: AA.BB.CC.DD data[4~5] Destination port data[6~7] rsvd; //Reserved	Yes
0x0006	pointcloud_host_ipcfg	8	uint8_t[8]	IP address configuration for pushing LiDAR point cloud data data[0~3] Point cloud destination IP address: AA.BB.CC.DD data[4-5] Point cloud destination port data[6~7] rsvd; //Reserved	Yes
0x0007	imu_host_ipcfg	8	uint8_t[8]	IP address configuration for pushing LiDAR IMU data data[0~3] IMU destination IP address: AA.BB.CC.DD data[4-5] IMU destination port data[6~7] rsvd; //Reserved	Yes
0x001A	work_tgt_mode	1	uint8_t	LiDAR target working mode (i.e. target working status), see (LiDAR Working Status)	Yes
0x001C	imu_data_en	1	uint8_t	0: IMU data push disabled 1: IMU data push enabled	Yes
0x0022	fov_mode	1	uint8_t	0: Focus Detection Mode 1: Normal Detection Mode, 350K points/s 2: Normal Detection Mode, 300K points/s 3: Normal Detection Mode, 250K points/s	Yes
0x0024	echo_mode	1	uint8_t	0: Sorted by echo intensity, single-echo output returns the strongest echo 1: Sorted by echo time, single-echo output returns the first returned echo	Yes
0x0025	NTP_server_ip	4	uint8_t[4]	IP address of the NTP server	Yes
0x0027	ITO_ctrl	1	uint8_t	Window glass heating enable: 0: Disable; 1: Force heating on 2: Constant-temperature automatic heating control	Yes
0x0028	fog_noise_filter	1	uint8_t	Rain and fog noise filter enable: 0: Disable; 1: Rain filtering; 2: Fog filtering	Yes
0x8000	sn	16	uint8_t[16]	String type (Use ‘\0’ padding for less than 16 bits) LiDAR SN (Use ‘\0’ padding for less than 16 bits)	No
0x8002	version_app	4	uint8_t[4]	App firmware version number: aa.bb.cc.dd version_info[0]: aa version_info[1]: bb version_info[2]: cc version_info[3]: dd	No
0x8003	version_loader	4	uint8_t[4]	Loader firmware version number	No
0x8006	cur_work_state	1	uint8_t	Current working state of LiDAR	No
0x8007	core_temp	4	int32_t	Core temperature (Unit: 0.01℃)	No
0x8010	FW_TYPE	1	uint8_t	Firmware type: 0: loader 1: application_image	No
0x0811	hms_code	32	uint32_t[8]	Diagnostic Trouble Code. Each non-0 value represents a piece of diagnostic information. When the LiDAR does not work normally, the cause of the problem can be confirmed through this diagnostic code	No

1.3.1.5.3. Control Command

1.3.1.5.3.1. 0x0200 Reboot Device

Request

CMD	Name	Offset(byte)	Data Type	Description
data	timeout	0	uint16_t	Reboot device delay time: ms

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.3.2. 0x0201 Restore Factory Settings

After this command is issued, the LiDAR will be restored to the factory settings. After the reply is successful, the LiDAR will reboot immediately to take effect.

Request

CMD	Name	Offset(byte)	Data Type	Description
data	SN	0	uint8_t[16]	Reserved

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.3.3. 0x0202 Set GPS Timestamp

Request

CMD	Name	Offset(byte)	Data Type	Description
data	type	0	uint8_t	Time synchronization method: 0-1: Reserved 2: GPS time synchronization
	time_set	1	uint64_t	If GPS synchronized, this field should be the time of the last rising edge of the PPS signal, the type is uint64_t, unit: ns

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.4. Log Command

1.3.1.5.4.1. 0x0300 Log file push

Requester: LiDAR

CMD	Name	Offset(byte)	Data Type	Description
data	log_type	0	uint8_t	Log type: 0 : real time log 3 : flash log
	file_index	1	uint8_t	File index
	file_num	2	uint8_t	This field is valid only when log_type is flash log, it means the number of flash log files
	flag	3	uint8_t	bit 0: 1 means need ack bit 1: 1 means create file bit 2: 1 means finish file Note: when the LiDAR sends the create file, sends the configuration information header, or ends the file data packet, the ack bit needs to be set
	timestamp	4	uint32_t	unix timestamp, this count starts at the Unix Epoch on January 1st, 1970 at UTC. When the host computer creates the log file, it uses the following naming rules: log_<log_type_name>_<file_index>_<system_time>.dat Example: log_fully_log_1_20220613203140.dat <system_time> is the system time converted from timestamp. If the timestamp returned by the LiDAR is 0, the host computer does not convert the timestamp and directly uses the host computer system time for naming
	rsvd	8	uint16_t
	trans_index	10	uint32_t	Send index
	log_data_len	14	uint16_t	Log content length
	log_data	16	–	Log content: Needs to be appended to the end of the file

Responder: Host computer

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)
	log_type	1	uint8_t
	file_index	2	uint8_t
	trans_index	3	uint32_t

1.3.1.5.4.2. 0x0301 Log collection configuration

Requester: Host computer

CMD	Name	Offset(byte)	Data Type	Description
data	log_type	0	uint8_t	Log type: 0 : real time log 3 : flash log
	enable	1	uint8_t	0 : disable 1 : enable

Responder: LiDAR

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.4.3. 0x0302 Log system time synchronization

Requester: Host computer

CMD	Name	Offset(byte)	Data Type	Description
data	timestamp	0	uint32_t	unix timestamp, this count starts at the Unix Epoch on January 1st, 1970 at UTC

Responder: LiDAR

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.4.4. 0x0303 Debug raw data collection configuration

Requester: Host computer

CMD	Name	Offset(byte)	Data Type	Description
data	enable	0	uint8_t	0: disable 1 : enable
	host_ip	1	uint8_t[4]	Debug raw data destination IP address: AA.BB.CC.DD data[0]: AA data[1]: BB data[2]: CC data[3]: DD
	host_port	5	uint16_t	Debug raw data destination port
	reserved	7	uint16_t	Reserved

Responder: LiDAR

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.5. General Upgrade

1.3.1.5.5.1. 0x0400 Request to Start Upgrade

Request

CMD	Name	Offset(byte)	Data Type	Description
data	firmware_type	0	uint8_t	Firmware type: 0: Package firmware 1: LiDAR firmware 2: Other firmware
	encrypt_type	1	uint8_t	Firmware encryption type: 0: None encrypt 1: AES128 2: AES256 3: DES 4: 3DES
	firmware_length	2	uint32_t	Total firmware length
	dev_type	6	uint8_t	Device type: 40: Avia2

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.5.2. 0x0401 Firmware Data Transmit

Request

CMD	Name	Offset(byte)	Data Type	Description
data	firmware_offset	0	uint32_t
	current_length	4	uint32_t
	encrypt_type	8	uint8_t
	rsvd	9	uint8_t[3]
	data	12	uint8_t[n]	Firmware data

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)
	current_offset	1	uint32_t
	received_length	5	uint32_t

1.3.1.5.5.3. 0x0402 Firmware Transmit Complete

Request

CMD	Name	Offset(byte)	Data Type
data	checksum_type	0	uint8_t
	checksum_length	1	uint8_t
	checksum_data	2	uint8_t[n]

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)

1.3.1.5.5.4. 0x0403 Get Firmware Upgrade State

Request

CMD	Name	Offset(byte)	Data Type	Description
data	NULL

ACK

ACK	Name	Offset(byte)	Data Type	Description
data	ret_code	0	uint8_t	Return code: (see (Return Code Description) for details)
	upgrade_progress	1	uint8_t	Upgrade progress: 0 ~ 100

1.3.1.6. Return Code Description

Name	Return Code	Description
LVX_RET_SUCCESS	0x00	Execution succeed
LVX_RET_FAILURE	0x01	Execution failed
LVX_RET_NOT_PERMIT_NOW	0x02	Current state does not support
LVX_RET_OUT_OF_RANGE	0x03	Setting value out of range

LVX_RET_PARAM_NOTSUPPORT	0x20	The parameter is not supported
LVX_RET_PARAM_REBOOT_EFFECT	0x21	Parameters need to reboot to take effect
LVX_RET_PARAM_RD_ONLY	0x22	The parameter is read-only and cannot be written
LVX_RET_PARAM_INVALID_LEN	0x23	The request parameter length is wrong, or the ack packet exceeds the maximum length
LVX_RET_PARAM_KEY_NUM_ERR	0x24	Parameter `key_num` and `key_list` mismatch

LVX_RET_UPGRADE_PUB_KEY_ERROR	0x30	Public key signature verification error
LVX_RET_UPGRADE_DIGEST_ERROR	0x31	Firmware digest signature verification error
LVX_RET_UPGRADE_FW_TYPE_ERROR	0x32	Firmware type mismatch
LVX_RET_UPGRADE_FW_OUT_OF_RANGE	0x33	Firmware length out of range
LVX_RET_UPGRADE_FW_ERASING	0x34	Firmware erasing

1.3.1.7. CRC Algorithm

CRC Name	Polynomial Formula	Width	Polynomial	Initial Value	Result XOR value	Input Reverse	Output Reverse
CRC-16/CCITT-FALSE	x^16^ + x^12^ + x^5^ + 1	16	0x1021	0xFFFF	0x0000	false	false
CRC-32	x^32^ + x^26^ + x^23^ + x^22^ + x^16^ + x^12^ + x^11^ + x^10^ + x^8^ + x^7^ + x^5^ + x^4^ + x^2^ + x + 1	32	0x04C11DB7	0xFFFFFFFF	0xFFFFFFFF	true	true