Example delay fan for bathroom

Maarten Hemker

In this example, we made a fan that only starts if the lights in the bathroom are on for longer than 1 minute, and then as soon as the lights go out, runs for 5 more minutes.



This top part of the logic uses a delay bit, to let through the "ON" command only after 1 minute. In case the lights go off within that minute, nothing happens. Therefore, the delay should be set to delay only "1 values" and to make sure the fan is never turned off directly, a filter bit is added, only allowing the "ON" command through.

The second part of the logic, is to start the timer when the lights go off again. To do this, the "OFF" command is inverted with an invert bit and compared to the current status of the fan with an and port. If this results in "TRUE" the lights have gone off and the fan is on. Then, the light timer should be triggered to keep the fan on for another 5 minutes. To make sure the fan is not stopped prematurely, the light timer should be set to "allow immediate off" = NO.