A Dcpslib should define at least one Topic or reference a Topic defined in another DcpsLib.
A Topic can be created by selecting topic from the palette. Alternative, a Topic defined in another DcpsLib can be referenced. This avoids needing to duplicate a Topic in multiple DcpsLibs. To place a Topic from another DcpsLib onto the current diagram:
These steps are illustrated below:
You can now link to this Topic as if it were defined within the original DcpsLib.
A Struct needs to be specified for the Topic's DataType. To pick from the allowed Structs, right click on the Topic to bring up the context menu. Pick "Select DataType" to bring up a dialog showing all the allowable Structs that you can pick from.
See Connecting DataReader/DataWriter to Topics for the steps on connecting a DataReader/DataWriter to your Topic/ContentFilteredTopic/MultiTopic.
A DataReader can optionally connect to a ContentFilteredTopic. Each ContentFilteredTopic must be connected to a Topic. Similar to a Topic, a ContentFilteredTopic must have a Struct specified for its DataType.
A DataReader can optionally connect to a MultiTopic. Similar to a Topic, a ContentFilteredTopic must have a Struct specified for its DataType.