Objects may not be connected to themselves without first going through another object. Pins are allowed only one connection each. Left click on an unused pin. It will turn green if it is available for connecting. With the left button still down, move the mouse to another pin on a different object.
Invalid connections turn red.
Assuming both pins are green, let up on the mouse. Both pins will jump out of their objects and appear as a double ended arrow, indicating the direction of signal flow. When moving object's, the triangles will try to point at their parking spot. Once a connection is made, either end may be moved to another location by clicking and dragging on the desired pin. Unconnecting Pins Hover the pin, and press the delete key.