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For a DataWriter and DataReader to communicate, they need to use the same Topic. A Topic includes a name and an association with a user data type that has been registered with Connext DDS. Topic names are how different parts of the communication system find each other. Topics are named streams of data of the same data type. DataWriters publish DDS samples into the stream; DataReaders subscribe to data from the stream. More than one Topic can use the same user data type, but each Topic needs a unique name.

Topics, DataWriters, and DataReaders relate to each other as follows:

Connext DDS uses ‘Builtin Topics’ to discover and keep track of remote entities, such as new participants in the DDS domain. Builtin Topics are discussed in Built-In Topics.

This section includes the following sections:


Topic QosPolicies

Status Indicator for Topics


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