Solar Guppy,

If it's a voltage-level issue, then trying on a different PC would still have the same problem, wouldn't it? (Unless the USB port weren't powered at all, but other devices don't have problems.)

I'll try an experiment just using a null-modem cable to another host to see if that works, but I'm returning to the idea that maybe it's the RS232 on the *inverter* that's the problem: its voltage levels are good enough for built-in RS232 ports, but not enough for the USB-to-serial cable. OK, seems unlikely, I know, but that's the only theory that fits all the facts.

I plan to use a Linux appliance, not a full-blown PC, with a USB memory stick as its nonvolatile memory. See this link: http://www.nslu2-linux.org/. I've measured power < 5W on mine.

Thanks for all your help!

- Matt

This is pretty interesting - The Linksys NSLU2 is a Router, and you reflash it with new firmware ? Can it run data collection apps, like GT View (via WINE)

Hmm, I don't think you could get it to work. I'm a Linux newbie, so I don't really know, but the memory restriction is pretty severe, and Wine would have to be ported to this platform, which is headless, so... no, I don't think that's an option.

Also, an update: Solar Guppy was right! My USB-to-serial cable *was* bad (could transmit but not receive), and now with a new one I can use GT-View just fine. (By the way, you can get *very* cheap USB cables on ebay!)

Uh, then what does the memory stick and the router do ? Do you have another box running GTview and doing what with memory & router ??