Communication Protocol

20 / 50

RPLIDAR will enter the measurement sampling mode once it receives the express

scan(EXPRESS_SCAN) request. Different from the scan(SCAN) request, this request

will make RPLIDAR work at the sampling rate as high as it can be. For LIDARs support

sampling more than 4000 times per second, the host system should use

GET_LIDAR_CONF command to get “Typical Scan Mode”, and use this command to

make LIDAR work under its best performance and output measurement sample data

accordingly.

The host system can use GET_LIDAR_CONF to get all scan modes, as well as

performance parameters, such as sample frequency, measurement range and etc.

The sample duration of standard and express mode could also be fetched via

command GET_SAMPLERATE.

RPLIDAR uses the same state machine and processing logic for this request as the

one of the scan(SCAN) request, but uses the different response format.

Format of the request packets:

The express scan(EXPRESS_SCAN) request is required to carry the 5 bytes payload

data and the data structure is shown as following. This payload data cannot be

omitted.

Figure 4-9 Format of a RPLIDAR Express Scan Data Request Packet

The descriptions of every field within the above data are listed in the following table:

working_mode

Reserved

Byte Offset