User Manual

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Basic Communication Mode

The RPLIDAR uses a non-textual binary data packet based protocol to communicate

with host systems. And all the packets transmitted on the interface channel share

uniform packet formats.

A communication session is always initialized by a host system, i.e. a MCU, a PC, etc.

RPLIDAR itself won’t send any data out automatically after powering up.

If a data packet is sent from host systems to RPLIDARs, such a packet is called a

Request. Once an RPLIAR receives a request, it will reply the host system with a data

packet called a Response.

RPLIDAR will only start performing related operations required by a host system

once after it receives a request. If RPLIDAR should reply to the host system, it will

send one or more required response packets.

In order to let an RPLIDAR start scanning operation and send out data, a host system

is required to send a pre-defined Start Scan request packet to RPLIDAR. RPLIDAR

will start scanning operation once after it receives the request and the scan result

data is sent out to the host system continuously.

There are three different request/response modes based on the related request

types:

Request/Response Modes

Figure 2-1 RPLIDAR Request/Response Modes

2. Protocol Basics

RPLIDAR

Host System

Send a Request Packet

Perform

Some

Operation

Reply a Response Packet

Waiting for

Response

Another Request