I'm new to programming the PLC
I'm trying to design a zoned HVAC system controller for a dual stage heat pump.
Most of the ladder logic is working but I'm trying to get a few extra features
After a heating/cooling call is finished, I'd like to keep the fan running and damper open for a set period of time to flush the conditioned air out of the system.
so, what is the most efficient way to create a limited time pulse width on the falling edge of a relay coil so that when the heating/cooling call is finished the fan runs a little longer?