On Thu, Jul 9, 2020 at 5:00 AM centos-request@centos.org wrote:
On Wed, Jul 08, 2020 at 01:40:27PM -0500, Chris Adams wrote:
Once upon a time, John Pierce jhn.pierce@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). https://www.google.com/search?q=serial+header+adapter
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