how_to_use_multi_cast_function.md

How to use multi-cast function

1 Introduction

This document will show you how to use rslidar_sdk to receive point cloud from the LiDAR working in multi-cast mode.

2 Steps (Linux)

Suppose the multi-cast address of LiDAR is 224.1.1.1.

2.1 Set up hiding parameters

User need to set up the hiding parameter multi_cast_address in lidar part of the config.yaml. Please check the Intro to hiding parameters for more details. Here is an example of the config.yaml.

common:
  msg_source: 1                                       
  send_packet_ros: false                                
  send_point_cloud_ros: true                            
  send_packet_proto: false                              
  send_point_cloud_proto: false                         
  pcap_path: /home/robosense/lidar.pcap     
lidar:
  - driver:
      lidar_type: RS128            
      frame_id: /rslidar           
      multi_cast_address: 224.1.1.1
      msop_port: 6699              
      difop_port: 7788             
      start_angle: 0               
      end_angle: 360             
      min_distance: 0.2            
      max_distance: 200           
      use_lidar_clock: false       

2.2 Set up the PC ip address

In multi-cast case, the ip address of PC has no limit but user needs to make sure the PC and LiDAR are in the same net work, which means PC can ping to LiDAR.

2.3 Add the PC to the group

Use the following command to check the PC's ethernet card name:

ifconfig

As the figure shows, the ethernet card name is enp2s0. Then execute the following command to add the PC to the group (replace the enp2s0 with your ethernet card name):

sudo route add -net 224.0.0.0/4 dev enp2s0

2.4 Run

Run the program.