Quote Originally Posted by Bruce View Post
Good points. Thanks. I'll look into what happens in suspend/hibernate. I wonder if networked PC's will drop-off the network in suspended or hibernate?
I've got a setting in my BIOS called 'WAKE ON LAN'. But, I'm not sure if that means 'WAKE up anytime you hear anything come across the RJ45 jack' or maybe 'WAKE whenever you see a packet with my MAC address come across', or what. Never tried it.
But I can tell you that my both of my laptop's, and 2 PC's (plus a Wii and 2 Axim's) maintain the same local IP on my local wireless using DHCP before and after using hibernate (memory dump to hard drive, system shut off) and/or standby (system shut off, but memory kept refreshed). But if I do a complete shutdown, yes, when they come back up, the IP is sometimes different than it was before.

I was thinking about the first post. You've got IR badges? I take it that they shoot out an IR signal at regular intervals? How about receiving that IR signal with a separate PIC and using that IR signal as a sort of 'CLEARWDT' in a program. The PIC doesn't get the IR signal and, if there is 5v on one of the hard drive power connectors, it kicks a relay which connects the power button, PC shuts down. Later, the IR signal returns, PIC sees it, check the 5v line on the power connector, kick the relay, PC powers up. Maybe 15 seconds before it shuts the PC down, it fires off a small beeper to warn that it's about to shut down the PC, in case the user is turned around talking to somebody or something like that.