On Thursday 26 February 2009 13:37, William L. Maltby wrote:
> > > Look in your /var/log/messages file. At boot, you should see the device
> > > recognized.
> >
> > Feb 26 12:12:25 borg2 kernel: serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is
> > a 16550A
> > Feb 26 12:12:25 borg2 kernel: serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is
> > a 16550A
>
> Didn't you say there was only one port? There might be a second on the
> main board that is accessible via a header. If it's not hooked up
> disable all but the first in the BIOS (later). It's not really hurting
> anything as is, but it will free the I/O address and IRQ for assignment
> to other devices.
I believe you are right. I remember those - and the 25-9-pin adapter :-).
Peering around the back in a dark corner, I could well have been mistaken.
OK - female socket, so that's a COM port, I think.
Now I'm really confused. The BIOS definitely only shows one COM port. To be
honest, I can't remember whether I connected it or not. I guess I ought to
open the box and see what's what, but not today - it's already too late to do
that.
> But wait until you have things working - I suspect you
> have _two_ ports (probably 1 9 pin and 1 25 pin). A second port of 25
> pins might easily be mistaken for a printer port. Long ago a switch from
> Centronics style to RS-232 style began to become the "standard".
> Physically, it looks the same as a serial port, the visual difference
> being the "gender" of the connector will be opposite.
>
> > Feb 26 12:12:25 borg2 kernel: 00:05: ttyS0 at I/O 0x3f8 (irq = 4) is a
> > 16550A
> >
> > Is this what I'm looking for? I don't see anything else.
>
> Yes. That means that all is as expected (i.e. as _I_ expect).
>
> > > Also, Minicom is _easy_ to use and understand. Give it a try. Even the
> > > man pages are not difficult.
> >
> > Easy when you know how, eh? :-) I did try it. I changed it to
> > monitor /dev/ttyS0. Apart from that, I hadn't a clue what to do. I did
> > look at the man page, too, but not knowing what I was looking for didn't
> > help.
>
> I haven't used it for a _long_ time, but IIRC there is an interactive
> menu system that works with some keystroke, maybe <ESC> key.
Ctrl-A Z - yes, I found that.
> Look for
> that stuff in the man pages and it should be clear sailing.
>
> First, have you set the baud rate correctly? A lot of things used to
> default to 9600, but 38400 became common later on. Do the docs for the
> unit specify? If so, use the stty command, or in minicom or other
> terminal emulator it's method, to set the baud rate to that needed.
> Usually these days, no parity check is done so 8 bit characters should
> be OK.
>
> Now, since the port is recognized the failure has to be from the port
> onward. If the RS-232 9 or 25 pin shell is connected via a cable to the
> main board, make sure that the cable connector is connected to the right
> header on the main board. Since Linux reported two ports, there should
> be two headers on the main board (_if_ that's the method - some ma
> inboards have them mounted directly on the main board). If the
> header/connector is not keyed, it may be connected backwards. If you
> have two RS-232D shells (9 or 25 pin) you may be connecting your cable
> to the wrong one.
>
I'll check all that out tomorrow. I only have a supplied cable for 9 pin, so
if everything else checks out I'll just have to try changing settings to
ttyS1 and see if that helps.
> Moving on, have you been able to verify the cable is good? If you have
> an RS-232 patch device with LED's, you can see activity (DTR, DCD, etc.)
> by hooking the cable to it. If you don't have one of those, a digital
> multi-meter can be used to see if you have expected voltages on certain
> pins (+/- 12 volts, IIRC). If you don't have one of those, a plain old
> dumb terminal can be hooked up and settings changed in a trial and error
> method.
>
I'm not handy with a multimeter, but if I have to, I'll give it a try :-)
> Since they supplied the cable, is it new enough to assume that it is not
> damaged? If so, I suspect something easy like baud rate.
Brand new. I know anything's possible, but I'd put a bad cable very low on
the list of likelihoods.
Settings at present:
A Serial Device : /dev/ttyS0
B Lockfile Location : /var/lock
C Callin Program :
D Callout Program :
E Bps/Par/Bits : 38400 8N1
F Hardware Flow Control : Yes
G Software Flow Control : No
All this is as set up in nut. Liebert do supply 'Multilink' software, but in
theory nut installs the latest Liebert Multilink drivers. I'm seriously
wondering whether I should remove nut and install the supplied software.
However, I realise that I need to check the hardware situation first.
Hopefully that will be done tomorrow.
Anne
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