Sometimes you don’t want the data that a node outputs. You just want the events.
One example is the composition below. The Fire Periodically node’s trigger port fires an event along with data — the number of seconds since the composition started — every 3 seconds. The Speak node doesn’t need or want that data. It just needs the event.
To create an event-only cable like the one below, start dragging from the Fired at Time port (pulling out a data-and-event cable), then drop the end of the cable onto the Speak input port. When you connect a data-and-event cable to an event-only port, the cable automatically becomes event-only.
It’s also possible to connect an event-only cable between a pair of data-and-event ports. This can be useful with the Count node, as shown below. Each time the Count node executes, it adds the amount in its Increment port to the total that it outputs. Let’s say you want to count up by 1 every 10 seconds. To control the timing, you can use the events from the Fire Periodically node’s trigger port, but you need to ignore the data from that port. You can accomplish this with an event-only cable.
To create this event-only cable, start dragging from the Fired at Time port. Hold down ⇧ (Shift) to change the cable from data-and-event to event-only, then drop the end of the cable onto the Increment port.
New in Vuo 2.0
Alternatively, you can drag the cable from the Fired at Time port and drop it into the title area of the Count node. Dropping the end of a cable onto a node’s title area changes the cable to event-only and connects it to the node’s first non-walled port.