Output control
IO (Set Digital I/O Lines) controls the output levels of D0 (DIO0/ADC0/Commissioning Configuration) through D7 (DIO7/CTS Configuration) that are configured as output pins (either 4 or 5). These values override the configured output levels of the pins until they are changed again (the pins do not automatically revert to their configured values after a timeout.)
You can use IO to trigger a sample on change detect.