[CentOS] Need to test serial port connection

Thu Feb 26 20:09:46 UTC 2009
Lanny Marcus <lmmailinglists at gmail.com>

On Thu, Feb 26, 2009 at 2:16 PM, Anne Wilson <cannewilson at googlemail.com> wrote:
> On Thursday 26 February 2009 18:55:22 William L. Maltby wrote:
>> On Thu, 2009-02-26 at 16:55 +0000, Anne Wilson wrote:
>> > On Thursday 26 February 2009 13:37, William L. Maltby wrote:
>> > <snip>
>> > > > 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
<snip>
> Oddly enough my husband can get quite tetchy if I spend more than 12 hours a
> day with a computer :-)

>> > > > Feb 26 12:12:25 borg2 kernel: 00:05: ttyS0 at I/O 0x3f8 (irq = 4) is
>> > > > a 16550A
>> BTW, someone mentioned RS-232C.

That was me (Lanny).

> That's the cable and electrical
>> specifications.
>> >
>> > 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
>>
>> Hardware flow control is suspect _if_ the device doesn't allow flow
>> until some event is seen, e.g. DTR or DCD and/or some information from
>> the device is ready to be transmitted. This could make it look like
>> nothing is working. But that really depends on how the device is
>> supposed to behave.

However, as I recall, if it works properly, it is always preferable to
use HW Flow Control and not SW Flow Control. Let the HW do the work,
if possible. (motto of how many SW Engineers?)

Anne: I suggest you check out the SW that is available for that UPS!
After I got home awhile ago, I took at look at the SW Download page
for the 3 off brand (made in Bogota, Colombia) Line Interactive UPS we
bought a few weeks ago. Here is the URL:

http://www.ups-software-download.com/winpower.htm

As you can see, their SW is available for a variety of OS, including
Linux (although not an .RPM). I am willing to bet the SW for your UPS
is also available for Linux. Check it out! (BTW, I have no idea what
language some of the stuff on that page is in. It is not Spanish....