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Lost USB comms after a killpower - BX700U | Back-UPS & Surge Protectors

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Lost USB comms after a killpower - BX700U

Discussion in Back-UPS & Surge Protectors started by John , 1/6/2018 5:26 PM
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Lost USB comms after a killpower - BX700U

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  • jradxl

    I have recently purchased a BX700U and am using it with apcupsd on three small servers and a  router, where the servers run Ubuntu 16.04 and Debian Stretch.

    I have been taking my setup through test cycles as I understand the operation of the BX700U and the apcupsd software for my first time.

    The following has happened to me twice now, and would be ridiculous if occurs regularly as I envisage unattended use...

    (a) I remove the power to the UPS and let the Master and two Slave work towards their shutdowns....
    (b) The Master issues a apcupsd --killpower followed by a shutdown -h now
    (c) as expected the Master shuts down and moments later, the UPS powers off.
    (d) the total power draw is about 25%, and I am testing with a TIMEOUT 240 parameter, so the battery is not being discharged by anything significant.
    (e) When the Power to the UPS is restored, all devices power up as expected.
    (f) HOWEVER there is no USB comms to the UPS.
    (g) the fix (so far twice) is to power off the UPS and remove the Yellow plug, and leave overnight.
    (h) Clearly ridiculous. Is this a known problem? Do I have a faulty unit?
    (i) This is NOT a problem with the USB cable, the USB port or the Server itself. All have been checked by substitutions, including the Powershute software on Windows 10. (g) is currently my only fix.

    UPS manufactured 3rd Dec 2017
    Software version : FIRMWARE : 924.Z3 .I USB FW:Z3

    Advice please
    Thank you

  • wpasquil


    The UPS should restore communication when it powers up. Is the UPS powering down completely? 

    On 1/6/2018 12:26 PM, John said:

    (g) the fix (so far twice) is to power off the UPS and remove the Yellow plug, and leave overnight

    What you are describing is similar the Bran Dead procedure. 

    1: Disconnect any attached load.

    2: Unplug the UPS from the wall socket.

    3: Disconnect the UPS' internal battery.

    4: Push and hold the "On" button on the UPS for 5 seconds

    5: Reconnect internal battery.

    6: Plug UPS in to known good power source.

    7: Turn UPS on.

    When the unit is brain dead the unit is reset so by you disconnecting the battery over night is appears the unit is resetting. 

  • ZSasha

    Hi Bill,

    I have similar issue. In fact this is the second time when that happened.

    I returned the first unit thinking something went wrong (because USB socket was a bit flimsy) and now it happened with the replaced unit as well.

    What had happened with me was that:

    1. I plugged the brand new UPS to a wall socket.

    2. Plugged USB cable to my server which was powered from another power source at that time (so nothing was connected to the UPS power sockets).

    3. Server could communicate with the UPS.

    4.Once I saw that working I moved all my stuff - router, WiFi and the server itself (it was a small Intel NUC machine) and plug all of them to the UPS.

    5.Powered the UPS up.

    6.Once server booted, I checked how it worked - no communications at all. In fact there was even no usb port created in linux, lsusb showed nothing, no reactions on inserting/removing the cable.

    Now the process you described above - should that be performed every time the UPS starts or when???
    I just confuse as to why that issue happens at the first place and how to fix that PERMANENTLY?! (Apart from swapping APC ups to some other, cheap Chinese models that actually do work without that headache) ?

    thank you. 

  • wpasquil
    This discussion is marked as answered


    Sorry for the inconvenience. The UPS should not lose comm with the computer after a restart. I suggest performing the reset procedure to resolve but no the procedure should not need to be done each time the system restarts. 

  • Xtof31fr
    This discussion is marked as answered

    Hi All,

    I just bought a new Back-UPS XS 700U.

    In order to try the efficiency of this new power device, after the full charge, I cut the power before the APC (with 10w of device behind the APC - 1 internet modem + 1 Raspberry PI + 1 smart device to pilot the roller shutters... No powerfull devices...)

    The APC does the job fine, keep the power to these devices during 15  minutes as expected (no load shutdown is defined for power < 15w) .  Then, the APC sends the shutdown signal (using the USB cable plugged between the APC and the raspberry pi) to ask raspberry Pi to shutdown. It works fine, all is OK...

    BUT, after the power recover, the APC restarts , the plugged devices restarts well , but the USB communication to the raspberry pi  is not working (no USB device detected using "lsusb"). Even if I'm trying to connect other PC / laptops etc... The USB port on the APC is frozen. It is fully inactive...

    I follow the steps to recover the USB (remove the power plug of the APC, the yellow plug, wait few minutes than I re-plug all again). USB is recovered after that.

    It is not normal to initiate a hard restart of the APC (removing the yellow plug) to recover the USB.

    I do the test 2 times, each time, the USB port is broken...

    Is the firmware of the APC has a known bug ? How to correct that ?

    The APC is under warrranty... May I return back the APC to Amazon ? Is it a known bug ?

    Thank your for your answer.


    root@hassbian:/var/log# apcaccess status

    APC      : 001,036,0870

    DATE     : 2019-07-16 21:25:35 +0200

    HOSTNAME : hassbian

    VERSION  : 3.14.14 (31 May 2016) debian


    CABLE    : USB Cable

    DRIVER   : USB UPS Driver

    UPSMODE  : Stand Alone

    STARTTIME: 2019-07-16 21:23:33 +0200

    MODEL    : Back-UPS XS 700U


    LINEV    : 234.0 Volts

    LOADPCT  : 2.0 Percent

    BCHARGE  : 100.0 Percent

    TIMELEFT : 160.5 Minutes

    MBATTCHG : 5 Percent

    MINTIMEL : 3 Minutes

    MAXTIME  : 0 Seconds

    SENSE    : Medium

    LOTRANS  : 140.0 Volts

    HITRANS  : 300.0 Volts

    ALARMDEL : 30 Seconds

    BATTV    : 13.4 Volts

    LASTXFER : No transfers since turnon

    NUMXFERS : 0

    TONBATT  : 0 Seconds

    CUMONBATT: 0 Seconds



    STATFLAG : 0x05000008

    SERIALNO : 3B1840X77987

    BATTDATE : 2018-10-07

    NOMINV   : 230 Volts

    NOMBATTV : 12.0 Volts

    NOMPOWER : 390 Watts

    FIRMWARE : 924.Z3 .I USB FW:Z3

    END APC  : 2019-07-16 21:26:12 +0200
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