Triggers block until a condition (such as a time interval, change in filesystem or arrival of mail in a mailbox) is met. When the condition is met, the Node returns execution back to the Workflow Manager which in turn passes control to Nodes downstream from the Trigger Node Execution Output. Once all downstream Nodes have executed, control is returned to the trigger.
It is therefore important that workflows are not connected in a cyclical fashion. Instead, Flowgear will contiguously pass execution to the Trigger Node. A Workflow that is activated in Always On mode should contain a trigger. If it does not, execution will terminate when the workflow has been processed.
Triggers can run In Cloud or at a DropPoint to provide very efficient execution when polling is not suitable.
To cause a Workflow to begin execution using a Trigger, enable Always On for the Workflow.
See https://flowgear.me/s/arxP7EK for an example of how to implement triggers.