Ubuntu Manpage: usbhid-ups - Driver for USB/HID UPS equipment

NAME

       usbhid-ups - Driver for USB/HID UPS equipment

SYNOPSIS

       usbhid-ups -h

       usbhid-ups -a UPS_NAME [OPTIONS]

           Note

           This man page only documents the hardware-specific features of the usbhid-ups driver. For information
           about the core driver, see nutupsdrv(8).

SUPPORTED HARDWARE

       usbhid-ups brings USB/HID UPS monitoring to NUT on all platforms supporting USB through libusb. It should
       detect any UPS that uses the HID Power Device Class, but the amount of data will vary depending on the
       manufacturer and model.

       At the present time, usbhid-ups supports:

       •   the newer Eaton USB models,

       •   all MGE USB models,

       •   all Dell USB models,

       •   all AMETEK Powervar UPM models,

       •   some APC models,

       •   some Belkin models,

       •   some Cyber Power Systems models,

       •   some Powercom models,

       •   some PowerWalker models,

       •   some TrippLite models.

       For a more complete list, refer to the NUT hardware compatibility list, available in the NUT source
       distribution as data/driver.list, or on the NUT website.

       You may use the explore driver option to gather information from HID UPSes which are not yet supported,
       to help add such support; see below for details.

       This driver is known to work on:

       •   most Linux systems,

       •   FreeBSD (beta stage) and maybe other *BSD,

       •   Darwin / Mac OS X,

       •   Solaris 10 and illumos-based distributions.

EXTRA ARGUMENTS

This driver also supports the following optional settings:

port = string
Some value must be set, typically auto.

Note
This could be a device filesystem path like /dev/usb/hiddev0 but current use of libusb API
precludes knowing and matching by such identifiers. They may also be inherently unreliable
(dependent on re-plugging and enumeration order). At this time the actual value is ignored, but
syntactically some port configuration must still be there.

It is possible to control multiple UPS units simultaneously by running several instances of this driver,
provided they can be uniquely distinguished by setting some combination of the vendor, product, vendorid,
productid, serial, bus and/or device options detailed below. For devices or operating systems that do not
provide sufficient information, the allow_duplicates option can be of use (limited and risky!)

vendorid = regex, productid = regex, vendor = regex, product = regex, serial = regex
Select a specific UPS, in case there is more than one connected via USB. Each option specifies an
extended regular expression (see regex(7) for more information on regular expressions), which must
match the UPS’s entire respective vendor/product/serial string values (minus any surrounding
whitespace), or the whole 4-digit hexadecimal code for vendorid and productid.

Try lsusb(8) or running this NUT driver with -DD command-line argument for finding out the strings to
match.

Examples:

• -x vendor="Foo.Corporation.*"

• -x vendorid="051d*" (APC)

• -x product=".*(Smart|Back)-?UPS.*"

bus = regex
Select a UPS on a specific USB bus or group of buses. The argument is a regular expression that must
match the bus name where the UPS is connected (e.g. bus="002" or bus="00[2-3]") as seen on Linux in
/sys/bus/usb/devices or lsusb(8); including leading zeroes.

device = regex
Select a UPS on a specific USB device or group of devices. The argument is a regular expression that
must match the device name where the UPS is connected (e.g. device="001" or device="00[1-2]") as
seen on Linux in /sys/bus/usb/devices or lsusb(8); including leading zeroes.

Note
device numbers are not guaranteed by the OS to be stable across re-boots or device re-plugging.

busport = regex
If supported by the hardware, OS and libusb on the particular deployment, this option should allow to
specify physical port numbers on an USB hub, rather than logical device enumeration values, and in
turn — this should be less volatile across reboots or re-plugging. The value may be seen in the USB
topology output of lsusb -tv on systems with that tool, for example.

Note
this option is not practically supported by some NUT builds (it should be ignored with a warning
then), and not by all systems that NUT can run on.

allow_duplicates
If you have several UPS devices which may not be uniquely identified by the options above (e.g. only
VID:PID can be discovered there), this flag allows each driver instance where it is set to take the
first match if available, or proceed to try another.

Normally the driver initialization would abort at this point claiming "Resource busy" or similar
error, assuming that the otherwise properly matched device is unique — and some other process already
handles it.

Warning
This feature is inherently non-deterministic! The association of driver instance name to actual
device may vary between runs!

If you only care to know that at least one of your no-name UPSes is online, this option can help.

If you must really know which one, it will not!

usb_set_altinterface = bAlternateSetting
Force redundant call to usb_set_altinterface(), especially if needed for devices serving multiple USB
roles where the UPS is not represented by the interface number 0 (default).

usb_config_index, usb_hid_rep_index, usb_hid_desc_index, usb_hid_ep_in, usb_hid_ep_out
Force use of specific interface, endpoint, descriptor index etc. numbers, rather than defaulting to 0
(rarely other values in certain drivers for some devices known to use non-zero numbers). Specified as
a hexadecimal number.

As a rule of thumb for usb_hid_desc_index discovery, you can see larger wDescriptorLength values
(roughly 600+ bytes) in reports of lsusb or similar tools.

LIBUSB_DEBUG = INTEGER
Run-time troubleshooting of USB-capable NUT drivers can involve not only raising the common NUT debug
verbosity (e.g. using the DEBUG_MIN setting in ups.conf(5) or protocol commands to change the
driver.debug value), but may also benefit from LibUSB specific debugging.

For the latter, you can set the LIBUSB_DEBUG driver option; alternatively you can classically export
the environment variable LIBUSB_DEBUG before starting a NUT driver program (may be set and "exported"
in driver init script or service method, perhaps via nut.conf(5)), to a numeric value such as 4 ("All
messages are emitted").

For more details, including the currently supported values for your version of the library, see e.g.:

• https://libusb.sourceforge.io/api-1.0/

• https://libusb.sourceforge.io/api-1.0/group__libusb__lib.html

subdriver=regex
Select the USB HID subdriver for the device manually, where automatic match by device attributes
alone does not suffice (e.g. new devices for which no vendorid/productid pair was built into any
driver — but common USB HID support is anticipated, or for different-capability devices with same
interface chips, notably "phoenixtec/liebert" and "mge").

Run the driver program with the --help option to see the exact list of subdriver values it would
currently recognize.

Note
This option first checks for exact matches to subdriver identification strings, such as
"TrippLite HID 0.85" (which are prone to bit-rot), and if there was no exact match — retries with
a case-insensitive extended regular expression.

Note
When using this option, it is mandatory to also specify the vendorid and productid matching
parameters.

lowbatt=num
Set the percentage at which the UPS will consider the battery charge as critically low, possibly
resulting in a forced shutdown (FSD) situation.

This value is typically dictated by the UPS device, although there is a fallback default value of 30
(in percent). Overriding this value can be helpful when the UPS sets this value to a lower percentage
than intended.

offdelay=num
Set the timer before the UPS is turned off after the kill power command is sent (via the -k switch).

The default value is 20 (in seconds), or 60 for CPS devices. Usually this must be lower than ondelay,
but the driver will not warn you upon startup if it isn’t.

Note that many Cyber Power Systems (CPS) models tend to divide this delay by 60 and round down, so
the minimum advisable value is 60 to avoid powering off immediately after NUT sends the shutdown
command to the UPS. More details below.

ondelay=num
Set the timer for the UPS to switch on in case the power returns after the kill power command had
been sent, but before the actual switch off. This ensures the machines connected to the UPS are, in
all cases, rebooted after a power failure.

The default value is 30 (in seconds), or 120 for CPS devices. Usually this must be greater than
offdelay, but the driver will not warn you upon startup if it isn’t. Some UPSes will restart no
matter what, even if the power is (still) out at the moment this timer elapses. In that case, you
could see whether setting ondelay = -1 in ups.conf helps.

Note that many CPS models tend to divide this delay by 60 and round down, so the minimum advisable
value is 120 to allow a short delay between when the UPS shuts down, and when the power returns.
According to support statement (for at least some CPS models), "our UPS systems are unable to set up
power on delay".

pollfreq=num
Set polling frequency for full updates, in seconds. Compared to the quick updates performed every
"pollinterval" (the latter option is described in ups.conf(5)), the "pollfreq" interval is for
polling the less-critical variables. The default value is 30 (in seconds), or 12 sec for CPS devices.

pollonly
If this flag is set, the driver will not use Interrupt In transfers during the shorter "pollinterval"
cycles (not recommended, but needed if these reports are broken on your UPS).

interrupt_pipe_no_events_tolerance=num
Set the tolerance for how many times in a row could we have "Got 0 HID objects" when using USB
interrupt mode? This may normally be due to a device having nothing urgent to report, so the default
value is -1 and this situation is not handled in any way specially. However with some devices this
was seen in conjunction with a frozen controller, where only a driver reconnection restored the data
exchange (e.g. APC BXnnnnMI) — in such cases you may want to use a reasonable non-negative value
here.

onlinedischarge_battery
If this flag is set, the driver will treat OL+DISCHRG status as offline/on-battery.

For most devices this combination means calibration or similar maintenance; however some UPS models
(e.g. CyberPower UT series) emit OL+DISCHRG when wall power is lost — and need this option to handle
shutdowns.

onlinedischarge
DEPRECATED, old name for onlinedischarge_battery described above.

onlinedischarge_calibration
If this flag is set, the driver will treat OL+DISCHRG status as calibration. Some UPS models (e.g.
APC were seen to do so) report OL+DISCHRG when they are in calibration mode. This usually happens
after a few seconds reporting an OFF state as well, while the hardware is switching to on-battery
mode.

Note
If it takes so long on your device that a shutdown gets issued, you may want to look at upsmon
option OFFDURATION used to filter out temporary values of "administrative OFF" as not a loss of a
feed for the powered load.

onlinedischarge_log_throttle_sec=num
Set the minimum frequency (in seconds) at which warnings would be emitted for an otherwise not
handled OL+DISCHRG device status combination. Negative values disable sequentially repeated messages
(when this state appears and persists).

If the device does not report battery.charge, the default value is 30 seconds (fairly frequent, in
case the UPS-reported state combination does reflect a bad power condition and so the situation is
urgent).

If it does report battery.charge, by default the repeated notifications would only be logged if this
charge is different from when the message was emitted previously (e.g. when the battery is really
discharging).

If both this option is set, and battery.charge is correctly reported, either of these rules allow the
notification to be logged.

onlinedischarge_log_throttle_hovercharge=num
See details in onlinedischarge_log_throttle_sec and battery.charge based log message throttling
description above. This option adds a concept of UPS "hovering" a battery charge at some level deemed
safe for its chemistry, and not forcing it to be fully charged all the time. As long as the current
value of battery.charge remains at or above this threshold percentage (default 100), the OL+DISCHRG
message logging is not triggered by variations of the charge.

lbrb_log_delay_sec=num
Set to delay status-setting (and log messages) about device entering LB or LB+RB state.

Some APC BXnnnnMI device models or firmware versions (reportedly 2023-2024) frequently report low
battery, replace battery, and all ok within a couple of seconds, sometimes but not always preceded by
OL+DISCHRG (presumably calibration). This setting lets the driver ignore short-lived states and only
pay attention if they persist longer than this setting (and the device power state is OL).

lbrb_log_delay_without_calibrating
Set to apply lbrb_log_delay_sec even if device is not calibrating.

disable_fix_report_desc
Set to disable fix-ups for broken USB encoding, etc. which we apply by default on certain models
(vendors/products) which were reported as not following the protocol strictly. This flag allows to
disable the feature in particular device configurations.

It is always possible that the vendors eventually release fixed firmware, or re-use identifiers by
which we match suspected broken devices for unrelated products, so processing these fix-ups would be
a waste of time there.

It is also always possible that NUT fix-ups cause issues on some devices, whether due to NUT bugs or
because the vendor protocol implementation is broken in more than one place.

powercom_sdcmd_byte_order_fallback
Original PowerCOM HID subdriver code (until version 0.7) sent UPS shutdown and stayoff commands in a
wrong byte order, than what is needed by actual devices seen in the field in 2024. The byte order is
fixed to satisfy new devices by default since version 0.71. Just in case there are different
firmwares out there with opposite behaviors, we provide this toggle to use old behavior in a
particular deployment. Maybe it was just a bug and nobody needs this fall-back...

explore
With this option, the driver will connect to any device, including ones that are not yet supported.
This must always be combined with the "vendorid" option. In this mode, the driver will not do
anything useful except for printing debugging information (typically used with -DD).

maxreport
With this option, the driver activates a tweak to workaround buggy firmware returning invalid HID
report length. Some APC Back-UPS units are known to have this bug.

interruptonly
If this flag is set, the driver will not poll UPS. This also implies using of INPUT flagged objects.
Some Powercom units need this option.

interruptsize=num
Limit the number of bytes to read from interrupt pipe. For some Powercom units this option should be
equal to 8.

waitbeforereconnect=num
The driver automatically tries to reconnect to the UPS on unexpected error. This parameter (in
seconds) allows it to wait before attempting the reconnection. The default value is 0.

Note
for instance, it was found that Eaton MGE Ellipse Max 1500 FR UPS firmware stops responding every
few hours, which causes usbhid-ups driver to detect an libusb insufficient memory error; in this
case, when the usbhid-ups driver tries to reconnect too early, the activity sometimes led the UPS
firmware to crash and turn off the load immediately! Setting this parameter to 30 seconds solved
this problem (while 20 seconds were not enough).

INSTALLATION

       This driver may be not built by default. You can build it by installing prerequisites and using configure
       --with-usb=yes. Note that it will also install other USB drivers.

       You also need to install manually the legacy hotplug files (libhidups and libhid.usermap, generally in
       /etc/hotplug/usb/), or the udev file (nut-usbups.rules, generally in /etc/udev/rules.d/) to address the
       permission settings problem. For more information, refer to the scripts/hotplug/README.adoc or
       scripts/udev/README.adoc files in NUT sources.

IMPLEMENTATION

Selecting a specific UPS
As mentioned above, the driver ignores the "port" value in ups.conf.

Unlike previous versions of this driver, it is now possible to control multiple UPS units simultaneously
with instances of this driver running in parallel, provided they can be distinguished by setting some
combination of the device-matching options.

For example:

[mge]
driver = usbhid-ups
port = auto
vendorid = 0463
[tripplite]
driver = usbhid-ups
port = auto
vendorid = 09ae

To monitor devices using the same vendor and product identification (e.g. two pieces of the same model),
you would need to find a reliable unique matching criteria:

• The serial number is the best option, if populated.

• Link-level bus/device/busport may be unreliable (due to re-enumeration on a whim by the operating
system).

• If nothing else helps, allow_duplicates may be an option in some cases.

USB Polling and Interrupt Transfers
The usbhid-ups driver has two polling intervals. The "pollinterval" configuration option controls what
can be considered the "inner loop", where the driver polls and waits briefly for "interrupt" reports. The
"pollfreq" option is for less frequent updates of a larger set of values, and as such, we recommend
setting that interval to several times the value of "pollinterval".

Many UPSes will respond to a USB Interrupt In transfer with HID reports corresponding to values which
have changed. This saves the driver from having to poll each value individually with USB Control
transfers. Since the OB and LB status flags are important for a clean shutdown, the driver also
explicitly polls the HID paths corresponding to those status bits during the inner "pollinterval" time
period. The "pollonly" option can be used to skip the Interrupt In transfers if they are known not to
work.

KNOWN ISSUES AND BUGS

UPS reports 65535 sec (or 18:12:15) of battery.runtime capability
From a number of reports, it seems that some devices either can not report more than a 16-bit unsigned
value in the standard field for remaining run time (vendor extended fields may exist but be unknown to
the mapping tables in your current NUT driver build), or return -1 for error and that gets treated as an
unsigned 16-bit 65535 value.

According to some issue discussions, passing a battery test (calibration) can help the UPS re-estimate
the time more correctly.

This problem may also be linked to a very lightly loaded large-capacity UPS. In some cases vendor
documentation explicitly states that runtime calculation is not reliable with loads under e.g. 10%.

Repetitive timeout and staleness
Some models tends to be unresponsive with the default polling frequency. The result is that your system
log will have lots of messages like:

usb 2-1: control timeout on ep0in
usb 2-1: usbfs: USBDEVFS_CONTROL failed cmd usbhid-ups rqt 128 rq 6 len 256
ret -110

In this case, simply modify the general parameter "pollinterval" to a higher value (such as 10 seconds).
This should solve the issue.

Note that if you increase "pollinterval" beyond 10 or 15 seconds, you might also want to increase
"pollfreq" by the same factor.

With certain devices and operating systems, notably MGE/Eaton USB Vendor ID (0x0463) on some versions of
the Linux kernel, you might encounter poor interaction with the "USB HID quirk" mechanism, which
precludes Linux from seeing the device as a hid-generic first, to hand it over to a NUT driver later. For
more details, see the NUT FAQ document. This particular quirk can be tuned with a kernel boot parameter
(via GRUB etc.):

usbhid.quirks=0x0463:0xffff:0x08

Conversely, some hardware controllers may "fall asleep" when not contacted for too long; CPS devices are
commonly associated with such behaviour. In this case, consider enabling pollonly flag and/or keeping
pollfreq and/or pollinterval small.

Got EPERM: Operation not permitted upon driver startup
You have forgotten to install the hotplug files, as explained in the INSTALLATION section above. Don’t
forget to restart hotplug so that it applies these changes.

Unattended shutdowns
The hardware which was used for development of this driver is almost certainly different from what you
have, and not all manufacturers follow the USB HID Power Device Class specifications to the letter. You
don’t want to find out that yours has issues here when a power failure hits your server room and you’re
not around to manually restart your servers.

If you rely on the UPS to shutdown your systems in case of mains failure and to restart them when the
power returns, you must test this. You can do so by running upsmon -c fsd. With the mains present, this
should bring your systems down and then cycle the power to restart them again. If you do the same without
mains present, it should do the same, but in this case, the outputs shall remain off until mains power is
applied again.

UPS cuts power too soon
Note that many Cyber Power Systems (CPS) models tend to divide offdelay by 60 and round down, so the
minimum advisable value is 60 (seconds) to avoid powering off immediately after NUT sends the shutdown
command to the UPS.

For many Cyberpower UPSs, offdelay must be set to 0 for normal behavior (the load is restored when AC
power returns). Setting offdelay above 0 will restart the UPS load regardless of whether or not power has
returned, and setting offdelay below 0 will disable the auto-power-on function of the UPS, keeping the
load off even when power returns.

UPS does not set battery.charge.low but says OK
Note that many Cyber Power Systems (CPS) models tend to allow only certain values for battery.charge.low
and anything outside of the set of allowed values are rounded or ignored.

A shell loop like this can help you map out the allowed values:

for i in `seq 90 -1 0`; do echo "set to $i"; \
upsrw -s battery.charge.low=$i -u * -p * cps-big; \
sleep 1; upsc cps-big battery.charge.low; echo ""; \
done

For example, for CPS PR1000LCDRTXL2U model, the only allowed values are [60,55,50,45,40,35,30,25,20] and
in some cases, your UPS may effectively not support a value of 10 for the battery.charge.low setting.

HISTORY

       This driver, formerly called newhidups, replaces the legacy hidups driver, which only supported Linux
       systems.

AUTHORS

       Originally sponsored by MGE UPS SYSTEMS.

       Now sponsored by Eaton http://opensource.eaton.com

       •   Arnaud Quette

       •   Peter Selinger

       •   Arjen de Korte