A seized motor looks exactly like a working one to the controller
The controller sends the command and the contactor closes, so from the panel the fan is on, even when a burnt winding or a tripped motor protector means nothing is turning.
A current sensor on the motor cable reads what the motor draws, so a stopped fan shows as zero within one reading.
A slipping belt costs air long before it breaks
A fan with a worn belt, a dirty shutter or a failing bearing keeps spinning but draws less current than it did the week it was serviced.
Each motor's lower limit is set from that motor's own readings, so a reading below it flags the fan that needs a technician before it stops.
A power cut stops every fan at once, and can take the alarm with it
When mains power fails, an alarm that runs on the same power fails with it.
The Genesis controller runs on its own rechargeable batteries and sends over the cellular network, so the moment every fan in the house drops to zero, the alert still reaches your phone.
Silence is also a signal
If a controller stops reporting altogether, because a cable was cut or a house lost its signal, the app raises a controller-offline alert rather than showing the last reading as if nothing happened.