Services are the basic building blocks for any application built with MSRS. Each service is used to accomplish a certain task, and several services can work together to accomplish a common goal. It is essential that these services can communicate. They do this by passing messages back and forth.

Services are created by using a built-in Visual Studio template, which creates the basic class structure needed to support a service. Services are started using the command-line tool DssHost.exe.

Services are like active documents, and the information they provide is known as the service’s state. The value of the state variables changes, depending on when it is requested, and it typically contains information such as sensor readings.

Service messages are sent and received through ports. A PortSet lists the operations that can be associated with a port and, thus, defines what types of messages the service can send and receive.

Services communicate with each other through the use of partnerships. One service can subscribe to another and receive notifications whenever the state has changed. This can be useful when there is a need to monitor a robot’s sensors or actuators.