Hi,
it's an old question, see here, but so far I have not heard about a practical solution. The quest is to find all instruments on a local LAN that are switched ON (and connected to the LAN, of course). Unfortunately, viFindRsrc does not work. Pinging all possible addresses seems not a viable solution due to the required time, either. So it's possible to detect all serial instruments, all instruments connected via GPIB, but until now there is no standalone solution (i.e.without involving NI-MAX) to detect instruments on a local LAN...
Thanks,
Wolfgang