On Wed, Jul 8, 2020 at 8:46 AM H <agents at meddatainc.com> wrote:> > I believe I mentioned that the UPS has the serial port, the computer thus > has USB. > >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. the latter DO use the serial data, and may work with USB serial. -- -john r pierce recycling used bits in santa cruz
> On Jul 8, 2020, at 10:58 AM, John Pierce <jhn.pierce at gmail.com> wrote: > > On Wed, Jul 8, 2020 at 8:46 AM H <agents at meddatainc.com> wrote: > >> >> I believe I mentioned that the UPS has the serial port, the computer thus >> has USB. >> >> > 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. > > the latter DO use the serial data, and may work with USB serial. > >John as always has the deepest insight (why I?m not surprised). Thanks ! Valeri> -- > -john r pierce > recycling used bits in santa cruz > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos
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. -- Chris Adams <linux at cmadams.net>
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. Fred -- ---- Fred Smith -- fredex at fcshome.stoneham.ma.us ----------------------------- I can do all things through Christ who strengthens me. ------------------------------ Philippians 4:13 -------------------------------
On 07/08/2020 02:40 PM, 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. >That's the issue but I will stay with a brand-name unit.
On 07/08/2020 11:58 AM, John Pierce wrote:> On Wed, Jul 8, 2020 at 8:46 AM H <agents at meddatainc.com> wrote: > >> I believe I mentioned that the UPS has the serial port, the computer thus >> has USB. >> >> > 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. > > the latter DO use the serial data, and may work with USB serial. > >I forgot to mention that I do have the serial cable for the APS UPS since the previous computer it supported did have a serial port. Thus, the only issue should be whether to buy a USB-serial adapter for the computer, or a card with a serial port.
On 07/08/2020 06:55 PM, H wrote:> On 07/08/2020 11:58 AM, John Pierce wrote: >> On Wed, Jul 8, 2020 at 8:46 AM H <agents at meddatainc.com> wrote: >> >>> I believe I mentioned that the UPS has the serial port, the computer thus >>> has USB. >>> >>> >> 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. >> >> the latter DO use the serial data, and may work with USB serial. >> >> > I forgot to mention that I do have the serial cable for the APS UPS since the previous computer it supported did have a serial port. Thus, the only issue should be whether to buy a USB-serial adapter for the computer, or a card with a serial port. >Closing out the above. I bought a Belkin USB-to-Serial adapter and after also getting the correct APC cable for this old APC BackupUPS things work as intended. Thus, no issues with the USB-to-serial adapter in this setting.