User manual

Exorcist User Manual
9
State vs. Event
Something that may confuse is the difference between State and Event, a light for
example has two states ‘ON’ or ‘OFF’, however; there are also two Events, i.e.
‘turning ON’ and ‘turning OFF’.
It’s important to understand this, because Exorcist is Event driven, not State Driven,
Exorcist responds to the Events of turning something ON or OFF, and not to the state
of ‘being ON’ or ‘being OFF.’
Normally this difference is just semantics, something normally can’t be ON unless it’s
turned on, and likewise it can’t be OFF unless it’s turned off. Sometimes when
Exorcist is armed and the inputs are already ON or OFF these states may be missed
and your Exorcist program logic will not seem to work properly.