ROS supports two main communication mechanisms: topics and services. Topics have publishers and subscribers and are used for sending and receiving messages (see ROS のパブリッシャーおよびサブスクライバーとのデータ交換). Services, on the other hand, implement a tighter coupling by allowing request-response communication. A service client sends a request message to a service server and waits for a response. The server will use the data in the request to construct a response message and sends it back to the client. Each service has a type that determines the structure of the request and response messages. Services also have a name that is unique in the ROS network.

ROS supports two main communication mechanisms: topics and services. Topics have publishers and subscribers and are used for sending and receiving messages (see ROS 2 のパブリッシャーとサブスクライバーとのデータ交換). Services, on the other hand, implement a tighter coupling by allowing request-response communication. A service client sends a request message to a service server and waits for a response. The server will use the data in the request to construct a response message and sends it back to the client. Each service has a type that determines the structure of the request and response messages.

ROS action workflow and communication protocols

This example shows how to use the /turtlebot_move action with a Turtlebot robot. The /turtlebot_move action takes a location in the robot environment and attempts to move the robot to that location.