The *nutscan_scan_nut()* function try to detect available NUT services and their associated devices. It issues a NUT request on every IP ranging from 'startIP' to 'stopIP'. 'startIP' is mandatory, 'stopIP' is optional. Those IP may be either IPv4 or IPv6 addresses or host names.
A specific 'port' number may be passed, or NULL to use the default NUT port.
This function waits up to 'usec_timeout' microseconds before considering an IP address does not respond to NUT queries.
RETURN VALUE
------------
The *nutscan_scan_nut()* function returns a pointer to a `nutscan_device_t` structure containing all found devices or NULL if an error occurs or no device is found.