3.3.1. Echo Participant

This Participant prints in stdout every data that is received by the DDS Router. The resulted logs contain the echo Participant Id, the source Endpoint Guid that has originally generated the message, the Topic where this message has been received, and the Payload (in hexadecimal format) received. Notice that this Payload is the same that a standard DDS DataReader will receive if it is connected to one of the Participants of the DDS Router.

Echo Participant: <participant_id> has received from Endpoint: <endpoint_guid> in topic: <endpoint_topic> the following payload: <payload>

This is an example of a message received by a DDS Router in a Participant connected to a ROS2 talker and written by an Echo Participant:

Echo Participant: ParticipantId{echo} has received from Endpoint: 01.0f.b8.a8.2e.69.b1.47.01.00.00.00|0.0.12.3 in topic: Topic{rt/chatter, std_msgs::msg::dds_::String_} the following payload: <Payload{00 01 00 00 0f 00 00 00 48 65 6c 6c 6f 20 57 6f 72 6c 64 3a 20 31 00 00}>

Note

This Participant does not perform any discovery or data reception functionality.

3.3.1.1. Use case

Use this Participant in order to see in stdout the data that is being relayed by the router. All the data received by any of the Participants of the router will be printed with timestamp, topic and source guid along with the payload.

3.3.1.2. Type aliases

• echo

3.3.1.3. Configuration

Echo Participant does not allow any configuration.

3.3.1.4. Configuration Example

echo_participant:       # Participant Id = echo_participant
    type: echo