On Thu, 2009-02-26 at 13:02 -0500, fred smith wrote: > <snip> > Let me just throw out one caveat here: Many UPSes that use a serial > port don't really utilize it to transfer serial data, but rather just > raise/lower some of the signal lines to let the software on the host > know something has changed. Of course, lots of them, especially newer/smarter ones > DO pass serial data. But if this one is one of the dumb ones, the cable may > not even be a normal rs-232 cable, so trying to monitor it with a terminal may not > produce much useful information. Yes. My intent was to debug the computer side first. With a terminal hooked up, you can echo directly to a ttyS{0,1,...} some short line and see if the characters are readable. Whne that is achieved, looking at the terminal settings will let you know baud, parity stop bits, flow control (possibly), etc. Once you know what one side of the cable is doing, then one can proceed to the other device. Divide and conquer. > <snip> -- Bill