Can't connect to PX4 uXRCE client

PX4 Autopilot
1

I could not connect PX4 using serial ports (TELEM x).

Hardware

A CUAV X7Plus with PX4 installed and a companion computer.

Environment

I’m using 1.16 of PX4 and have installed MicroXRCEAgent on the computer and enabled uxrce_dds_client on the board.

What’s going on

I could not maintain the connection with the board.

» ./MicroXRCEAgent serial -D /dev/ttyUSB0 -b 921600

[1764175505.675389] info     | TermiosAgentLinux.cpp | init                     | running...             | fd: 3
[1764175505.675515] info     | Root.cpp           | set_verbose_level        | logger setup           | verbose_level: 4
[1764175506.294005] info     | Root.cpp           | create_client            | create                 | client_key: 0x00000001, session_id: 0x81
[1764175506.294047] info     | SessionManager.hpp | establish_session        | session established    | client_key: 0x00000001, address: 1
[1764175507.297575] info     | Root.cpp           | delete_client            | delete                 | client_key: 0x00000001
[1764175507.297599] info     | SessionManager.hpp | destroy_session          | session closed         | client_key: 0x00000001, address: 1
[1764175508.302981] info     | Root.cpp           | create_client            | create                 | client_key: 0x00000001, session_id: 0x81
[1764175508.303004] info     | SessionManager.hpp | establish_session        | session established    | client_key: 0x00000001, address: 1

nsh> uxrce_dds_client stop
nsh> uxrce_dds_client start -t serial -d /dev/ttyS3
INFO  [uxrce_dds_client] init serial /dev/ttyS3 @ 921600 baud
nsh> ERROR [uxrce_dds_client] create entities failed: participant: 255
ERROR [uxrce_dds_client] session setup failed, will retry now
INFO  [uxrce_dds_client] init serial /dev/ttyS3 @ 921600 baud
ERROR [uxrce_dds_client] create entities failed: participant: 255
ERROR [uxrce_dds_client] session setup failed, will retry now
INFO  [uxrce_dds_client] init serial /dev/ttyS3 @ 921600 baud
ERROR [uxrce_dds_client] create entities failed: participant: 255
ERROR [uxrce_dds_client] session setup failed, will retry now
INFO  [uxrce_dds_client] init serial /dev/ttyS3 @ 921600 baud
ERROR [uxrce_dds_client] create entities failed: participant: 255
ERROR [uxrce_dds_client] session setup failed, will retry now
INFO  [uxrce_dds_client] init serial /dev/ttyS3 @ 921600 baud
ERROR [uxrce_dds_client] create entities failed: participant: 255
ERROR [uxrce_dds_client] session setup failed, will retry now
INFO  [uxrce_dds_client] init serial /dev/ttyS3 @ 921600 baud

No error info if I do not start the agent.