I need to connect an older APS UPS unit to a machine running CentOS 7. Unfortunately the UPS only has a serial port whereas the computer does not. I am aware that there are USB-serial adapters but that the hardware or the drivers might fall short of expectations. Does anyone have positive experience with such an adapter? Or, conversely, would recommend avoid a particular adapter?
If it is an older APC UPS, that uses basic serial signaling, it's not actually a serial port, it's a criss-cross special serial cable that manages the control lines with DSR DTR CTS and so forth. these are very fussy cables that have to be exactly the right one or the UPS may just abruptly shut off. As far as USB serial cables go, the FTDI ones have always worked well for me,at least for applications that actually use the serial port for serial data On Wed, Jul 8, 2020, 8:14 AM H <agents at meddatainc.com> wrote:> I need to connect an older APS UPS unit to a machine running CentOS 7. > Unfortunately the UPS only has a serial port whereas the computer does not. > I am aware that there are USB-serial adapters but that the hardware or the > drivers might fall short of expectations. > > Does anyone have positive experience with such an adapter? Or, conversely, > would recommend avoid a particular adapter? > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >
I've used one on a Linux laptop, it "just worked" but the OS wasn't CentOS 7. ________________________________ From: CentOS <centos-bounces at centos.org> on behalf of H <agents at meddatainc.com> Sent: Wednesday, July 8, 2020 10:13 AM To: Centos Mailing List <centos at centos.org> Subject: [EXTERNAL] [CentOS] USB-serial adapter for CentOS 7 CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. I need to connect an older APS UPS unit to a machine running CentOS 7. Unfortunately the UPS only has a serial port whereas the computer does not. I am aware that there are USB-serial adapters but that the hardware or the drivers might fall short of expectations. Does anyone have positive experience with such an adapter? Or, conversely, would recommend avoid a particular adapter? _______________________________________________ CentOS mailing list CentOS at centos.org https://lists.centos.org/mailman/listinfo/centos Harriscomputer Leroy Tennison Network Information/Cyber Security Specialist E: leroy at datavoiceint.com [cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG] 2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.com<http://www..com> This message has been sent on behalf of a company that is part of the Harris Operating Group of Constellation Software Inc. If you prefer not to be contacted by Harris Operating Group please notify us<http://subscribe.harriscomputer.com/>. This message is intended exclusively for the individual or entity to which it is addressed. This communication may contain information that is proprietary, privileged or confidential or otherwise legally exempt from disclosure. If you are not the named addressee, you are not authorized to read, print, retain, copy or disseminate this message or any part of it. If you have received this message in error, please notify the sender immediately by e-mail and delete all copies of the message.
On 7/8/20 11:14 AM, H wrote:> I need to connect an older APS UPS unit to a machine running CentOS 7. Unfortunately the UPS only has a serial port whereas the computer does not. I am aware that there are USB-serial adapters but that the hardware or the drivers might fall short of expectations. > > Does anyone have positive experience with such an adapter? Or, conversely, would recommend avoid a particular adapter?I've been using Belkin & Prolific USB serial adapters on Centos & Fedora for years. They just work.> _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos-- Roger Wells, P.E. leidos 221 Third St Newport, RI 02840 401-847-4210 (voice) 401-849-1585 (fax) roger.k.wells at leidos.com
I've several USB <-> RS-232 dongles around. As well as a few embedded devices. They all "Just Work (tm)" on Redhat, CentOS, Fedora, Debian, Raspian and Kali. Knock on wood - never had a problem using any of them. As the drivers are part of the kernel, I'd expect any distro using a recent kernel to do well. On Wed, Jul 8, 2020 at 9:24 AM Leroy Tennison <leroy at datavoiceint.com> wrote:> I've used one on a Linux laptop, it "just worked" but the OS wasn't CentOS > 7. > > ________________________________ > From: CentOS <centos-bounces at centos.org> on behalf of H < > agents at meddatainc.com> > Sent: Wednesday, July 8, 2020 10:13 AM > To: Centos Mailing List <centos at centos.org> > Subject: [EXTERNAL] [CentOS] USB-serial adapter for CentOS 7 > > CAUTION: This email originated from outside of the organization. Do not > click links or open attachments unless you recognize the sender and know > the content is safe. > > > I need to connect an older APS UPS unit to a machine running CentOS 7. > Unfortunately the UPS only has a serial port whereas the computer does not. > I am aware that there are USB-serial adapters but that the hardware or the > drivers might fall short of expectations. > > Does anyone have positive experience with such an adapter? Or, conversely, > would recommend avoid a particular adapter? > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos > > Harriscomputer > > Leroy Tennison > Network Information/Cyber Security Specialist > E: leroy at datavoiceint.com > > > > [cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG] > > > 2220 Bush Dr > McKinney, Texas > 75070 > www.datavoiceint.com<http://www..com> > > > This message has been sent on behalf of a company that is part of the > Harris Operating Group of Constellation Software Inc. > > If you prefer not to be contacted by Harris Operating Group please notify > us<http://subscribe.harriscomputer.com/>. > > > > This message is intended exclusively for the individual or entity to which > it is addressed. This communication may contain information that is > proprietary, privileged or confidential or otherwise legally exempt from > disclosure. If you are not the named addressee, you are not authorized to > read, print, retain, copy or disseminate this message or any part of it. If > you have received this message in error, please notify the sender > immediately by e-mail and delete all copies of the message. > > > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >-- Tate Belden "The Dungeon <http://ka7o.net>" We are dreamers, shapers, singers and makers. We study the mysteries of laser and circuit, crystal and scanner, holographic demons and invocations of equations. These are the tools we employ, and we know many things. --Elric
On 2020-07-08 10:23, Leroy Tennison wrote:> I've used one on a Linux laptop, it "just worked" but the OS wasn't CentOS 7. >It is not clear if you used USB from APC UPS to USB port on the machine side or USB - to - "serial". USB to USB with standard USB cable will work. If one uses serial to USB adapter on the machine side (to create serial port through USB on the machine), then one _has_to_use_ APC cable: as John Pierce just said, it is APC special cable which though has serial connectors on both sides of cable, (and uses serial protocol of communication - this is already what I am saying), it does not resemble neither serial nor null-modem cables. Valeri> ________________________________ > From: CentOS <centos-bounces at centos.org> on behalf of H <agents at meddatainc.com> > Sent: Wednesday, July 8, 2020 10:13 AM > To: Centos Mailing List <centos at centos.org> > Subject: [EXTERNAL] [CentOS] USB-serial adapter for CentOS 7 > > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > I need to connect an older APS UPS unit to a machine running CentOS 7. Unfortunately the UPS only has a serial port whereas the computer does not. I am aware that there are USB-serial adapters but that the hardware or the drivers might fall short of expectations. > > Does anyone have positive experience with such an adapter? Or, conversely, would recommend avoid a particular adapter? > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos > > Harriscomputer > > Leroy Tennison > Network Information/Cyber Security Specialist > E: leroy at datavoiceint.com > > > [cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG] > > > 2220 Bush Dr > McKinney, Texas > 75070 > www.datavoiceint.com<http://www..com> > > > This message has been sent on behalf of a company that is part of the Harris Operating Group of Constellation Software Inc. > > If you prefer not to be contacted by Harris Operating Group please notify us<http://subscribe.harriscomputer.com/>. > > > > This message is intended exclusively for the individual or entity to which it is addressed. This communication may contain information that is proprietary, privileged or confidential or otherwise legally exempt from disclosure. If you are not the named addressee, you are not authorized to read, print, retain, copy or disseminate this message or any part of it. If you have received this message in error, please notify the sender immediately by e-mail and delete all copies of the message. > > > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >-- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++
Check the voltages on your adapter. I use such adapters in the machine shop so machinists can share the CNC programs they write on a PC with their CNC controllers. The CNC controllers can be fussy about voltages, and some cheap RS232-USB adapters only generate +/-5vdc. It's within the RS232 spec and newer RS232 chips are happy with that, but older systems might want 12v or more. Another issue is handshake lines. Not all adapters provide all the handshake lines. Some are "3-wire" data-only with only ground, transmit, and receive connected. Some devices will want 5 or 7 wire connections, with RTS/CTS and DTR/DSR signals included. Check that the adapter you buy provides all the signals your device needs. Which service are you using to manage your UPS? Nut? Something else? They probaby have a mailing list, website, or wiki where you can find out what adapters work well with which UPS units. (Be sure to post back here when you get an answer.)