On Thu, 2009-02-26 at 06:14 -0500, Phil Schaffner wrote:
> On Thu, 2009-02-26 at 10:17 +0000, Anne Wilson wrote:
> ><snip>
> > There is just one serial connector on the computer, so I set it to
> > monitor /dev/ttyS0. Either that is wrong, or communication is failing.
> > I've been told to try minicom to monitor it, but I'm not familiar with
> > minicom (or any similar app), so again, I may be wrong in the way I'm trying
> > to use that. I was told that unconnecting the device, then re-connecting it
> > should give me a raft of output to the terminal - I saw nothing.
> >
> > Could someone please give me idiot-level instructions on how to tell whether
> > I'm connecting to the correct port, or whatever other information I need?
>
> Anne,
>
> Are you sure the cable is correct? I recall in the past having trouble
> with an APC UPS that required an oddball RS-232 serial cable before it
> would communicate. There were different variants available and only one
> would work. Posting details of the brand/model of UPS involved might
> get better help.
OTOH, if the manufacturer has any common sense, at worst they'll require
a "standard" (NOT!) null-modem cable. At best, they'll have
circuitry/software on-board that accepts either a straight-through or
null and adapts itself.
Being an _old_ telecom guy from way back, I prefer what was called a
symmetrical null modem fully configured. From memory (and therefore
suspect)
Pin---->Pin
2 3
3 2
4 4
6 6
7 7
8 20
20 8
Some also do 5 to 5.
However, a 2-3 cross and DTR and DCD high is all that really is needed.
Google for RS-232 will get you a ton of stuff.
As to the OP original question, check BIOS settings and make sure your
serial is enabled. Set it to COM 3 and IRQ 4 should work. This would
equate to "0" in an *IX system.
Look in your /var/log/messages file. At boot, you should see the device
recognized.
Also, Minicom is _easy_ to use and understand. Give it a try. Even the
man pages are not difficult.
>
> Phil
> <snip sig stuff>
HTH
--
Bill
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