Hardware that supports monitoring will display different information about hardware status, like temperature, voltage.
Routers that support voltage monitoring will display supplied voltage value. In CLI/Winbox it will display volts. In scripts/API/SNMP this will be dV or value showed in CLI/Winbox multiplied by 10
Routers that support temperature monitoring will display temperature reading. In CLI/Winbox it will display degrees Celsius. In scripts/API/SNMP this will be value showed in CLI/Winbox multiplied by 10
Using this menu users will be able to control fan behaviour on the router.