Malcom ... Good find. I am sending a copy to TrippLite Tech Support for verification. Unlike the previous web site, the cable depicted at the following web site (you provided) seems to match my measurements, and the documentation for genericups 5. http://www.exploits.org/nut/library/tripplite.html The ups software changes the RTS line pin-7 to +12v, and leaves DTR line pin-4 at -12v. Yet the diagram says +V. So, not everything adds up for me. To a computer person, the pin-assignments on the TrippLite (and other UPS units) and associated cables seem rather odd -- evidently not designed by a comphter hardwre person. But then, the computer hardware designers did not use pin-1 as ground, which is an unwritten electronic standard. TrippLite did stick with pin-1 as ground. Now if I could just understand why my computer does not shut down when I simulate contact closures... ... Reed, alta@alta-research.com On Friday 15 February 2002 06:31, you wrote:
On Friday 15 February 2002 01:08, alta wrote:
I am attempting to get a TrippLite BC PRO 850 interfaced for automatic shutdown (as mentioned in earlier post). Any clues why all the weirdness?
Hi Reed.
I have two TrippLites, which is why I was interested in your problem. I may want to connect mine to shutdown their boxes in the future.
I dug around a bit more with Google and came up with this:
http://www.exploits.org/nut/library/tripplite.html
This supposedly is the schematic of an actual TrippLite shutdown cable.
I'm not sure how this compares with the diagram on the other site, but when I look at the diagram the labeling doesn't make any sense. For example, pin 5 on the PC end is SG (signal ground), an unchanging value. Calling it Inverter Shutoff - is a bit unclear.
Also, pin 3, PC end, is not ground. It's the send data line (SD).
This is somewhat of a an educated guess, but I think that the UPS grounds its pins 5 and/or 6 as appropriate to signal to the PC. Normally, the PC keeps its pins 8 and 1 high via pin 4 through the resistors. The UPS gets its ground on its pin 4. UPS pin 2 gets the shut down signal from the PC when pin 7 goes high.
I suspect that the top line labeled ground is actually a serial data line that is uses to send data to the bigger, high priced UPSes, and is not used by small UPS applications.
All of the above should be taken with the understanding that I have not actually measured any of this, and nothing I've said is guaranteed. <backpedals furiously> {:^)>
Anyway, perhaps this will help.
Good luck.
-- Reed White - ALTA RESEARCH - www.alta-research.com Phone: 877-360-2582 - Email: alta@alta-research.com