Generally this driver should work for all the APC Modbus UPS
devices. Some devices might expose more than is currently supported, like
multiple phases. A general rule of thumb is that APC devices (or firmware
versions) released after 2010 are more likely to support Modbus than the USB
HID standard.
Tested with the following hardware:
•SMT1500 (Smart-UPS 1500, Firmware 9.6)
•SMX750 (Smart-UPS X 750, Firmware 10.1)
•SMX1500 (Smart-UPS X 1500, Firmware 15.0)
Note that you will have to enable Modbus communication. In the
front panel of the UPS, go to Advanced Menu mode, under Configuration and
enable Modbus.
Note
This driver was tested with Serial, TCP and USB interfaces for
Modbus. Notably, the Serial ports are not available on all devices nowadays;
the TCP support may require a purchase of an additional network management
card; and the USB support currently requires a non-standard build of
libmodbus (pull request against the upstream library is pending, as of at
the time of this publication) as a pre-requisite to building NUT with this
part of the support. For more details (including how to build the custom
library and NUT with it) please see NUT PR #2063
Note
As currently published, this driver supports reading information
from the UPS. Implementation of support to write (set modifiable variables
or send commands) is expected with a later release. This can impact the host
shutdown routines in particular (no ability to actively tell the UPS to
power off or cycle in the end). As a workaround, you can try integrating
apctest (from the "apcupsd" project) with a "Test to kill
power" into your late-shutdown procedure, if needed.
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 (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).
porttype=value
Set the type of the port used. Available values are
serial for RS232/485 based connections, tcp for TCP/IP connections and usb for
USB connections.
port=value
Depending on the port type you can select a port here.
For usb only auto is supported, for serial you can pass a device path like
/dev/ttyS0 and for tcp you can pass a hostname with optional port like
example.com:502.
baudrate=num
Set the speed of the serial connection. The default
baudrate is 9600.
parity=value
Set the parity of the serial connection. Available values
are N for none, E for even and O for odd. The default parity is N
(none).
databits=num
Set the data bits of the serial connection. The default
databits is 8.
stopbits=num
Set the stop bits of the serial connection. The default
stopbits is 1.
slaveid=num
Set the Modbus slave id. The default slave id is 1.
response_timeout_ms=num
Set the Modbus response timeout. The default timeout is
set by libmodbus. It can be good to set a higher timeout on TCP connections
with high latency.