Normally, gates require parent gates (those connected to their left-side ports) to push (send an event) to them before starting the processing. For instance, in the following case, the 'clock' gate will not start until the 'play' gate connected to its 'start' port produce an event.
However, some ports support a mode called 'getValue', which allows them to 'read' the value of their parent gate in a passive mode, in other words, without the parent gate having to 'push' anything to them. These ports are identified by a light blue colour. In the following example, the 'Counter' gate, reads the value from the 'Value' gate attached to it before increasing its number:
Notice that there is nothing on the left of the 'Value' gate 'pushing' the value to the 'Counter', but the counter is still able to 'read' the value '3' and use it for its internal processing.