There are 3 ways of making connections
1 Connecting predefined points
In this case you must select Line mode. When you move the mouse over a symbol, all of it's predefined connection points appear. Click on one of these and then as you move the mouse the connections for other symbols are made visible. Provided they are compatible you can make the connection.
2 Add New from one end
This starts the same as when connecting predefined points however you can then click on a symbol and make a new connection to match the one you have started. ControlDraw will prompt to make sure this is what you want to do.
3 Drag from centre to centre of symbols
In this case, a new connection is made. this adopts the default signal for the class of the symbol at the origin of the connection, as defined in the Class Table.
With methods 1 and 2 you can also connect from a symbol on one diagram to a symbol on another. Open two diagrams and you can start from a connection point for a symbol on the first diagram and end on a symbol in the second diagram.
You must be in multi window style to do this.