[CentOS] CentOS Digest, Vol 186, Issue 8

Thu Jul 9 16:06:01 UTC 2020
Rich Greenwood <rgreenwood at shastacoe.org>

On Thu, Jul 9, 2020 at 5:00 AM <centos-request at centos.org> wrote:

> On Wed, Jul 08, 2020 at 01:40:27PM -0500, Chris Adams wrote:
> > Once upon a time, John Pierce <jhn.pierce at gmail.com> said:
> > > yes, but is it 'basic serial UPS' or is it 'enhanced serial UPS' ?
> the
> > > former do NOT use the rx/tx data of the serial port at all, they ONLY
> use
> > > the serial port control  signals, and they probably will NOT work with
> a
> > > USB port because they require very specific behavior from those
> signals at
> > > power up and reboot times.
> >
> > I've used various serial devices, including UPSes, via various
> > USB-to-serial adapters (Prolific PL2303 and FTDI FT2232C), and all the
> > signaling works fine.  Only issue you sometimes have is that there are
> > many cheap adapters on Amazon that claim to be Prolific or FTDI but are
> > in fact counterfeit clones - those may or may not work reliably for ANY
> > purpose.
> >
> Another possibility for the Original Poster:
> Purchase a serial add-in card from Amazon or Newegg.
> last I noticed they weren't expensive. This avoids
> the compatibility-hell you may (or may not) encounter
> with a USB-to-serial converter.

One more possibility that nobody has mentioned yet is to see if the
motherboard has a serial port header.   Many motherboards still have an
actual serial port that doesn't show up on the edge as a 9-pin, but on the
board as a 10-pin header.  You can get the header adapter for a few dollars
(or maybe in your junk drawer).

Also, I just plugged in a PL2303 based adapter to a CentOS 8 machine
yesterday to connect to a Cisco serial console and it just worked.

Rich Greenwood
Network Engineer
Shasta County Office of Education