HUAWEI_UPS2000(8)
==================

NAME
----

huawei-ups2000 - Driver for Huawei UPS2000 (1kVA-3kVA) UPS with USB or
RS-232 serial Modbus connection.

SYNOPSIS
--------

*huawei-ups2000* -h

*huawei-ups2000* -a 'DEVICE_NAME' ['OPTIONS']

NOTE: This man page only documents the hardware-specific features of the
huawei-ups2000 driver.  For information about the core driver, see
linkman:nutupsdrv[8].

SUPPORTED HARDWARE
------------------

This driver supports Huawei UPS2000 series, online (double conversion)
UPS with the following characteristics.

1. Output power: 1 kVA to 3 kVA (higher power models are unsupported).

2. Connection: USB or RS-232 (USB is only supported on Linux 5.12 and
newer kernels, read the section *Cabling* carefully).

The UPS2000 series has two variants: UPS2000-A with a tower chassis,
and UPS2000-G with a rack-mount chassis. Both should be equally supported,
but more testers are needed.

Currently, it has been tested on the following models.

* UPS2000-A-1KTTS (firmware: V2R1C1SPC40, P1.0-D1.0)
* UPS2000-A-2KTTS (firmware: V2R1C1SPC50, P1.0-D1.0)
* UPS2000-G-3KRTS (firmware: V2R1C1SPC40, P1.0-D1.0)

If your model is not in the list, we encourage you to report successful
or unsuccessful results to the bug tracker or the mailing list.
Make sure to include the full model number of your UPS manually
in your report, because the firmware only reports "UPS2000-A"
for all models, including the G series.

huawei-ups2000 uses the libmodbus project, for Modbus implementation.

CABLING
-------

The UPS has a USB port and a RS-232 port. Both are supported, but USB is
only usable on Linux 5.12 and later, via the *xr_serial* kernel module (see
subsection *USB* for details). RS-232 is supported on all operating systems.

Only one port can be used at a time. When USB is used, RS-232 should be
unplugged from the UPS, and vice versa. Further, optional adapter cards,
such as RS-485 or SNMP, are not supported. They should be removed from
the UPS.

Because the UPS port can be unresponsive under certain circumstances, it's
recommended to power cycle your UPS after making a cabling change, especially
after changing the port type. That is, turn off the UPS power output via the
front panel, then unplug the UPS from line power input.  Wait for the LCD
screen to go black. Finally reconnect line power and restart your UPS.

USB
~~~~

The USB port on the UPS2000 is powered by a MaxLinear/Exar RX21V1410
USB-to-serial converter chip, it's only supported by Linux 5.12 or
newer, via the *xr_serial* kernel module.

When the UPS2000 is connected via USB to a supported Linux system,
you should see the following logs in *dmesg*.

    xr_serial 1-1.2:1.1: xr_serial converter detected
    usb 1-1.2: xr_serial converter now attached to ttyUSB0

The driver must be *xr_serial*. If your system doesn't have the
necessary device driver, you will get this message instead:

    cdc_acm 1-1.2:1.0: ttyACM0: USB ACM device

The generic driver *cdc_acm* is incompatible and cannot be used.
You should upgrade your Linux kernel to Linux 5.12 or newer.

WARNING: On an unsupported system, the USB device can still be
recognized as a USB ACM device, but communication is impossible,
please don't waste your time on *cdc_acm*.

If you're already running on Linux 5.12 or newer kernels, but still
cannot see the *xr_serial* driver, it means the driver is not enabled
in your kernel build. If you're a regular user, you should file a bug
report to your Linux distro maintainers and ask them to enable
*xr_serial* (kernel option `CONFIG_USB_SERIAL_XR`).

When upgrading the Linux kernel isn't an option, or when you are using
another operating system (e.g. FreeBSD), RS-232 must be used.

RS-232
~~~~~~

RS-232 is supported on all operating systems, either via a built-in serial
port on your computer, or by using an external USB-to-RS-232 converter. If
you plan to use an USB-to-RS-232 converter, make sure it's supported by your
operating system.


INSTALLATION
------------

This driver is not built by default.  You can build it by installing libmodbus
(with development packages) and running

    configure --with-serial=yes --with-modbus=yes

You also need to give proper (R/W) permissions on the local serial device file
to allow the NUT driver run-time user to access it. This may need additional
setup for start-up scripting, udev or upower rules, to apply the rights on every
boot -- especially if your device nodes are tracked by a virtual filesystem.

For example, a USB-to-serial converter can be identified as `/dev/ttyACM0`
or `/dev/ttyUSB0` on Linux, or `/dev/ttyU0` on FreeBSD (note the capital "U").
A built-in serial port can be identified as `/dev/ttyS0` on Linux or one of
`/dev/cua*` names on FreeBSD.

EXTRA ARGUMENTS
---------------
This driver supports the following optional settings in the
linkman:ups.conf[5] file:

*offdelay=*'value'::
Time to wait before shutting down the UPS (seconds), acceptable range is
6 seconds (0.1 minutes) to 5940 seconds (99 minutes). Defaults to 60 seconds.
Must be a multiple of 6 seconds. To ensure your system has adequate time
to shut down after a power failure, it's highly recommended to adjust
*offdelay*.

*rebootdelay=*'value'::
Time to wait before rebooting the UPS (seconds), acceptable range is
6 seconds (0.1 minutes) to 5940 seconds (99 minutes). Defaults to 60 seconds.
Must be a multiple of 6 seconds. This is used by the *shutdown.reboot.graceful*
instant command. If you've adjusted *offdelay*, you should also adjust
*rebootdelay*.

*ondelay=*'value'::
Time to wait before switching on the UPS (seconds), acceptable range is
60 seconds (1 minutes) to 5940 seconds (99 minutes). Defaults to 60 seconds.
Must be a multiple of 60 seconds (not 6 seconds). You don't need to adjust
this delay unless you have special requirements.

NOTE: Due to hardware limitation, in this driver, *ondelay* is respected
only when line power is available. If a power failure has occurred, the
UPS and the load is always immediately switched on, as soon (or as late)
as line power is restored.

INSTANT COMMANDS
----------------

This driver supports some instant commands (see linkman:upscmd[8]):

*shutdown.stayoff*::
After an *offdelay*, turn off the load. When line power is back,
remain off.

*shutdown.return*::
After an *offdelay*, turn off the load. When line power is back,
turn on the load, possibly after an *ondelay*.

NOTE: Normally, the load is turned on as soon as line power is back.
But if line power is never lost, or has came back unexpectedly
in the middle of an ongoing shutdown (an undesirable "power race"
condition that many entry-level products on the market fail to
recover from), the load is turned on after an *ondelay*. Thus,
UPS2000 is unaffected by a power race, the load is guaranteed to
always restart.

*shutdown.reboot*::
Like *shutdown.return*, except that the load is turned off immediately
(6 seconds in this implementation).

*shutdown.reboot.graceful*::
Like *shutdown.return*, except that the load is turned off after a
*rebootdelay*, not an *offdelay*.

*beeper.enable*::

Enable the UPS beeper.

*beeper.disable*::

Disable the UPS beeper.

*beeper.toggle*::

Toggle the UPS beeper.

*bypass.start*::

Put the UPS in bypass mode. Use with caution. It exposes your equipment
to unregulated line power and provides no protection from power failures.
Also, the UPS may shut down whenever the bypass input voltage is out
of the nominal range. As a warning, the UPS beeps once every 10 seconds
in bypass mode.

NOTE: The driver has a basic foolproof mechanism. If the bypass input
is already abnormal due to a power failure, the driver refuses to enter
bypass mode by aborting the command and logging an error. However, it
offers no protection after the UPS has entered (or in the middle of
entering) bypass mode. Thus, again, use with caution.

*bypass.stop*::

Put the UPS out of bypass mode.

*load.on*::

Turn on the load immediately.

*load.off*::

Turn off the load immediately. Use with caution, everything on the UPS
will lost power.

*test.battery.start.quick*::

Perform a short battery test.

*test.battery.start.deep*::

Perform a long battery test.

*test.battery.stop*::

Stop a running battery test.

VARIABLES
---------

This driver supports some writable runtime variables (see linkman:upsrw[8]):

**ups.beeper.status**::
Enable or disable the UPS beeper, *disabled* or *enabled*.

NOTE: The beeper can only be disabled completely, it cannot be
temporally muted until the next alarm, but the option *muted* is
also accepted for convenience, *muted* is treated as an alias of
*disabled*.

**ups.delay.shutdown**::
Seconds to wait after shutdown with delay command. It's the runtime
equivalent of *offdelay*. See description of *offdelay*.

**ups.delay.reboot**::
Seconds to wait before rebooting the UPS, it's the runtime
equivalent of *rebootdelay*. See description of *rebootdelay*.

**ups.delay.start**::
Seconds to wait before restarting the load, it's the runtime
equivalent of *ondelay*. See description of *ondelay*.

KNOWN ISSUES AND BUGS
---------------------

Battery status has a non-fatal read failure
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It's usually harmless and can be safely ignored. It's only logged for
informative purposes (*LOG_INFO*), not as a warning or error.

Data stale
~~~~~~~~~~~

Under certain circumstances, some registers can return invalid values
and trigger a "data stale" error. Once a data stale error has occurred,
you should see error messages similar to the example below in the system
log.

    huawei-ups2000: register 2002 has invalid value a000,
    upsd: Data for UPS [huawei] is stale - check driver
    upsd: UPS [huawei] data is no longer stale

So far all known problems have been fixed by the author, but an unknown one
cannot be ruled out. If you have encountered "data stale" problems during
normal uses, please file a bug report with full logs attached.

Before troubleshooting or reporting a problem, it's important to check
your *dmesg* log for USB connect and disconnect events to avoid wasting
time on the NUT driver when the actual problem is USB. For example, if
someone yanks the cable out of the USB port, or if a new USB device is
plugged into a USB host/hub that is struggling to power its ports
(common on single-board computers like Raspberry Pi), or if you have
flaky cabling or EMI noise, the serial converter can get disconnected
from USB, at least briefly. This creates a permanent data stale, the driver
must be restarted (plugging the USB back won't fix it, since the driver
is still using the nonexistent serial device). These USB problems usually
have nothing to do with NUT. If it's the case, you should solve the
underlying USB problem - check the cable, check the converter, try a
powered USB hub, try a full-speed USB isolator, etc.

Serial port becomes unresponsive
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Some malformed commands are known to lock up the serial port (including
USB, which is a USB-to-serial device). Upon receiving them, UPS2000 stops
all serial communications. The result is a completely unresponsive UPS,
regardless of what you do - restarting NUT, rebooting the computer -
cannot restore connectivity, as if someone has unplugged the RS-232 cable.
To recover, simply power cycle the UPS: Turn off the UPS output via the
front panel, then unplug the UPS from line power. Wait for the LCD front
screen to go black. Finally reconnect line power and restart your UPS.

That being said, a serial port lockup is unlikely to happen. To our best
knowledge, this driver never sends malformed commands to the UPS (it was
only a problem during early development). Furthermore, due to a CRC checksum,
they're unlikely to be accidentally generated.

Still, we recommend to power cycle your UPS after making a cabling change,
especially after changing from RS-485/USB to RS-232, just to ensure the
UPS selects the correct communication interface. Also, if you have
discovered a reproducible serial port lockup problem, it can be an
previously unknown bug, make sure to file a bug report.

USB is unsupported
~~~~~~~~~~~~~~~~~~~

As previously stated, only RS-232 is supported on all systems. USB
requires a device-specific driver, which is only available on Linux
5.12 and newer kernels.

On an unsupported system, the USB device can still be recognized as a
USB ACM device, but in reality, communication is impossible. It can
only be fixed by implementing a driver for your system, nothing can
be done within NUT.

Finally, in the unlike scenario that you are using NUT on Microsoft
Windows, you should be able to install the USB device driver following
the steps in the Huawei UPS2000 (1 kVA-3 kVA) Modbus Protocol Development
Guide.

AUTHOR
------

Yifeng Li <tomli@tomli.me>

SEE ALSO
--------

The core driver:
~~~~~~~~~~~~~~~~

linkman:nutupsdrv[8]

Internet resources:
~~~~~~~~~~~~~~~~~~~

* The NUT (Network UPS Tools) home page: http://www.networkupstools.org/
* Huawei UPS2000-A (1 kVA-3 kVA) User Manual:
  https://support.huawei.com/enterprise/en/doc/EDOC1000084260
* Huawei UPS2000 (1 kVA-3 kVA) Modbus Protocol Development Guide:
  https://support.huawei.com/enterprise/en/doc/EDOC1000110696
* libmodbus home page: http://libmodbus.org
