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@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@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@centos.org on behalf of H agents@meddatainc.com Sent: Wednesday, July 8, 2020 10:13 AM To: Centos Mailing List centos@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@centos.org https://lists.centos.org/mailman/listinfo/centos
Harriscomputer
Leroy Tennison Network Information/Cyber Security Specialist E: leroy@datavoiceint.com
[cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG]
2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.comhttp://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 ushttp://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.
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@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@centos.org on behalf of H < agents@meddatainc.com> Sent: Wednesday, July 8, 2020 10:13 AM To: Centos Mailing List centos@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@centos.org https://lists.centos.org/mailman/listinfo/centos
Harriscomputer
Leroy Tennison Network Information/Cyber Security Specialist E: leroy@datavoiceint.com
[cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG]
2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.comhttp://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 ushttp://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@centos.org https://lists.centos.org/mailman/listinfo/centos
On 2020-07-08 11:28, Tate Belden wrote:
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.
Even if you did have an RS232 port on the box, the serial drivers for CentOS 7 have never worked correctly. I had an application using RS232 that worked perfectly under CentOS 6, and then worked intermittently under CentOS 7, and failed miserably on CentOS 8. The handwriting on the RedHat wall says, "nobody uses RS232 anymore!" I moved the app to a Raspberry Pi 3B+, using the USB serial adapters, and it works perfectly again.
Todd Merriman Software Toolz, Inc.
-> "nobody uses RS232 anymore!"
Somebody needs to update the hand writing on the wall, although the physical hardware may be an RJ-45, the RS232 protocol is still used on headless devices and probably other things. I use minicom more than I wish but it's still required. ________________________________ From: CentOS centos-bounces@centos.org on behalf of mailist mailist@toolz.com Sent: Wednesday, July 8, 2020 11:11 AM To: CentOS mailing list centos@centos.org Subject: [EXTERNAL] Re: [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.
Harriscomputer
Leroy Tennison Network Information/Cyber Security Specialist E: leroy@datavoiceint.com
[cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG]
2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.comhttp://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 ushttp://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 2020-07-08 11:28, Tate Belden wrote:
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.
Even if you did have an RS232 port on the box, the serial drivers for CentOS 7 have never worked correctly. I had an application using RS232 that worked perfectly under CentOS 6, and then worked intermittently under CentOS 7, and failed miserably on CentOS 8. The handwriting on the RedHat wall says, "nobody uses RS232 anymore!" I moved the app to a Raspberry Pi 3B+, using the USB serial adapters, and it works perfectly again.
Todd Merriman Software Toolz, Inc. _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Once upon a time, mailist mailist@toolz.com said:
Even if you did have an RS232 port on the box, the serial drivers for CentOS 7 have never worked correctly. I had an application using RS232 that worked perfectly under CentOS 6, and then worked intermittently under CentOS 7, and failed miserably on CentOS 8. The handwriting on the RedHat wall says, "nobody uses RS232 anymore!"
I've used serial ports just fine on CentOS 7 (haven't had a physical CentOS 8 system so far, so can't say there, but have used serial consoles on CentOS 8 VMs), as well as newer Fedora (similar but newer kernels). Are you sure you weren't doing something in an unsupported and/or undefined way that just happened to work on CentOS 6?
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@centos.org on behalf of H agents@meddatainc.com Sent: Wednesday, July 8, 2020 10:13 AM To: Centos Mailing List centos@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@centos.org https://lists.centos.org/mailman/listinfo/centos
Harriscomputer
Leroy Tennison Network Information/Cyber Security Specialist E: leroy@datavoiceint.com
[cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG]
2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.comhttp://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 ushttp://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@centos.org https://lists.centos.org/mailman/listinfo/centos
On July 8, 2020 11:39:29 AM EDT, Valeri Galtsev galtsev@kicp.uchicago.edu wrote:
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@centos.org on behalf of H
Sent: Wednesday, July 8, 2020 10:13 AM To: Centos Mailing List centos@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
- 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@centos.org https://lists.centos.org/mailman/listinfo/centos
Harriscomputer
Leroy Tennison Network Information/Cyber Security Specialist E: leroy@datavoiceint.com
[cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG]
2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.comhttp://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 ushttp://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@centos.org https://lists.centos.org/mailman/listinfo/centos
I believe I mentioned that the UPS has the serial port, the computer thus has USB.
On Jul 8, 2020, at 10:46 AM, H agents@meddatainc.com wrote:
On July 8, 2020 11:39:29 AM EDT, Valeri Galtsev galtsev@kicp.uchicago.edu wrote:
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@centos.org on behalf of H
Sent: Wednesday, July 8, 2020 10:13 AM To: Centos Mailing List centos@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
- 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@centos.org https://lists.centos.org/mailman/listinfo/centos
Harriscomputer
Leroy Tennison Network Information/Cyber Security Specialist E: leroy@datavoiceint.com
[cid:Data-Voice-International-LOGO_aa3d1c6e-5cfb-451f-ba2c-af8059e69609.PNG]
2220 Bush Dr McKinney, Texas 75070 www.datavoiceint.comhttp://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 ushttp://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@centos.org https://lists.centos.org/mailman/listinfo/centos
I believe I mentioned that the UPS has the serial port, the computer thus has USB.
In this case, if UPS doesn’t have USB port (which will be much simpler), then as others said:
1. use USB to serial dongle attached to computer USB port (check with standard serial communicating equipment that your computer with this dongle talks serial protocol)
2. Get APC cable; this is not standard serial cables, standard cables (neither serial nor null-modem) will not work. It probably will be something like this:
https://www.amazon.com/dp/B000067OG4?tag=duckduckgo-ffsb-20&linkCode=osi...
- but take it with a grain of salt, do your own checking.
Then you will be in business.
I used APC smart UPSes for almost a couple of decades. With cables as above connected to serial port of machine (those were CentOS Linuxes). I used apcupsd, which also can be configured as master on machine directly connected to UPS, and several other machines, behind the same UPS power wise though not connected to UPS signal wise, but talking to apcupsd on master machine.
Good luck!
Valeri
On Wed, Jul 8, 2020 at 8:46 AM H agents@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.
On Jul 8, 2020, at 10:58 AM, John Pierce jhn.pierce@gmail.com wrote:
On Wed, Jul 8, 2020 at 8:46 AM H agents@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@centos.org https://lists.centos.org/mailman/listinfo/centos
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.
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.
Fred
On 07/08/2020 03:02 PM, Fred Smith 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.
Fred
OK, I'll see what fits the machine best.
On 07/08/2020 02:40 PM, 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.
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@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@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.
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@centos.org https://lists.centos.org/mailman/listinfo/centos
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.)
-
Chris Adams -
Fred Smith -
H -
John Pierce -
Kenneth Porter -
Leroy Tennison -
mailist -
Tate Belden -
Valeri Galtsev -
Wells, Roger K.