This command, enable notification events due to status change of the relative GPIx or GPIO pin.
Unsolicited events help to monitor inputs without need of a continuous polling.

GPIO <GPI1/GPI2/GPIO> NOTIFY

OK

EVNT <GPI1/GPI2/GPIO> <ON/OFF>

GPIO GPI1 NOTIFY
OK
...
EVNT GPI1 ON
...
GPIO GPIO NOTIFY
OK
...
EVNT GPIO OFF