5.1.3 Connecting Components

We are now ready to connect the components. Right-click the ``TxDemo1'' instance and select ``Connect'' to open the ``Connections'' window. The left pane lists all the ports owned by ``TxDemo1'' which should just include symbols_out. The TxDemo component itself generates a sequence of QPSK symbols that are pushed by this port.

The right pane lists all the ports associated with the components and devices currently included in the waveform. Click the drop arrow next to ``Components.'' You should see a list of all the component instances and their available ports. As indicated by the legend, a black box indicates a uses port while a white box indicates a provides port. Generally speaking, a uses port is an output interface while a provides port is an input interface. There are a few rules to remember when connecting ports:

1. A provides port must be connected to a uses port, and vice versa
2. Both ports must be of the same interface or data type (e.g. complexShort)

From the left pane select the ``TxDemo1'' uses port symbols_out. From the right pane, under ``Components'', select the ``ChannelDemo1'' provides port samples_in. Click the ``Connect'' button in the center of the window to establish the connection. The ``Connections'' pane should now indicate this connection:

Select ``OK'' to confirm the connection you specified. This returns you to the main OWD window. You should now see a drop arrow next to the ``TxDemo1'' component instance. Clicking the arrow reveals all connections made by the component. Repeat these steps to connect the ``ChannelDemo1'' uses port samples_out to the ``RxDemo1'' provides port ``symbols_in.'' Start by right-clicking on the ``ChannelDemo1'' component and selecting ``Connect.''