<div dir="ltr"><div><span style="background-color:transparent">Just had a lengthy conversation with someone, thought it was on the list, here's the recap.</span></div><div><br></div><div>I tried on different computers - Pi 2 Zero W, Pi 5, higher-end AMD. All Linux Debian Trixie, which is what I run.<br>Was through powered hubs. Tried different powered hubs, different USB ports on each computer, different cables. Tried the "good" cable (the one for the UPS that returned 100% of the time, and it made no difference on the other UPS, and their cables worked fine on the one "good" UPS.<br><br>I guess the basic question is, is this common with less-expensive UPS like those, that they're not reliably connected?<br>If not, not sure what else I can do to test?<br><br></div><div>Are there configuration settings to control how long nut-scanner collects info, or what fields it requires before returning info?<br>Perhaps something like a timeout setting or cache or ?<br>(I didn't dive into the code.)<br><br></div><div><br></div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Mon, Sep 7, 2026 at 5:29 PM Bruce Pleat <<a href="mailto:bpleat@gmail.com">bpleat@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hi,</div><div>I recently build 2.8.5 from the latest (as of a week ago) code.</div><div>I noticed that nut-scanner produces very inconsistent results for some of my 6 UPS.</div><div>There's quite the spread in both how often they respond and how well one of them responds. In 600 runs, with varying pauses between them, with two analyses performed, and with uniq giving the frequency:</div><div> 15 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501"<br> 66 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="ABST600",vendor="CPS"<br> 319 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="SL Series",vendor="CPS"<br> 370 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="CP685AVR-G",vendor="CPS"<br> 500 USB:driver="usbhid-ups",port="auto",vendorid="051D",productid="0002",product="Back-UPS ES 600M1",serial="4B1936P07680",vendor="American Power Conversion"<br> 500 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="ABMT1500",serial="FCEMU2001294",vendor="CPS"<br>...so two are reliable, four are not.</div><div><br></div><div>With a slightly different call to get the USB bus info (since two of the UPS are identical models):</div><div> 2 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",bus="001",busport="002"<br> 56 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="ABST600",vendor="CPS",bus="001",busport="003"<br> 59 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="ABST600",vendor="CPS",bus="001",busport="001"<br> 73 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="SL Series",vendor="CPS",bus="001",busport="002"<br> 81 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="CP685AVR-G",vendor="CPS",bus="001",busport="002"<br> 101 USB:driver="usbhid-ups",port="auto",vendorid="0764",productid="0501",product="ABMT1500",serial="FCEMU2001294",vendor="CPS",bus="001",busport="001"<br> 106 USB:driver="usbhid-ups",port="auto",vendorid="051D",productid="0002",product="Back-UPS ES 600M1",serial="4B1936P07680",vendor="American Power Conversion",bus="001",busport="003"<br><br>bus="001",busport="001",vendorid="0764",productid="0501",vendor="CPS",product="ABMT1500",serial="FCEMU2001294"<br>bus="001",busport="001",vendorid="0764",productid="0501",vendor="CPS",product="ABST600",serial=<br>bus="001",busport="002",vendorid="0764",productid="0501",vendor="CPS",product="CP685AVR-G",serial=<br>bus="001",busport="002",vendorid="0764",productid="0501",vendor="CPS",product="SL Series",serial=<br>bus="001",busport="002",vendorid="0764",productid="0501",vendor=,product=,serial=<br>bus="001",busport="003",vendorid="051D",productid="0002",vendor="American Power Conversion",product="Back-UPS ES 600M1",serial="4B1936P07680"<br>bus="001",busport="003",vendorid="0764",productid="0501",vendor="CPS",product="ABST600",serial=</div><div><br></div><div>I believe both the USB bus is not always reporting all six (I checked that and saw lsusb not giving consistent results), but also the UPS themselves seem to be inconsistent.</div><div><br></div><div>I tried swapping cables, changing the USB port on the test computer, and more.</div><div><br></div><div>I'd rather not waste perfectly good UPS, and I'd rather not go live with this unreliability.</div><div><br></div><div>Thoughts on how I can diagnose this further?</div><div><br></div><div>Thanks.</div><div><br></div></div>
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