[deano_ferrari]

I can only have a guess at this because I've only had experience of brother scanner connected on network at work.

I think there should be a config tool called hp-setup with which you can supply the IP address of your scanner on the network:

hp-setup -a 192.168.1.88 (for example)

If all went well, you should get some useful output when you invoke the following command as regular user:

scanimage -L

If you don't get a response, try again as root. See how that goes. Maybe someone else has more experience with this hardware.