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DUMMY-UPS(8)			  NUT Manual			  DUMMY-UPS(8)

       dummy-ups - Driver for multi-purpose UPS	emulation

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

       This program is a multi-purpose UPS emulation tool. Its behavior
       depends on the running mode: "dummy" or "repeater".

   Dummy Mode
       In this mode, dummy-ups looks like a standard NUT device	driver to
       upsd(8) and allows one to change	any value for testing purposes.	It is
       both interactive, controllable through the upsrw(1) and upscmd(1)
       commands	(or equivalent graphical tool),	and batchable through script
       files. It can be	configured, launched and used as any other "real" NUT
       driver. This mode is mostly useful for development and testing

   Repeater Mode
       In this mode, dummy-ups acts as a NUT client, simply forwarding data.
       This can	be useful for supervision purposes. This mode can also allow
       some load sharing between several upsd instances	communicating with
       ultimate	NUT clients, with a "central" one using	a point-to-point
       communication with the UPS. This	arrangement can	also help with
       networked UPSes,	whose network management cards can be overwhelmed with
       a farm of servers directly polling SNMP or other	protocols every	few

       The port	specification in ups.conf depends on the running mode, and
       allows the driver to select the right mode of operation.

   Dummy Mode
       In this context,	port in	the ups.conf block defines a file name for the
       dummy-ups to read data from. This can either be an absolute or a
       relative	path name. In the latter case the NUT sysconfig	directory
       (i.e. /etc/nut, /usr/local/ups/etc, ...)	is prepended.

       For instance:

		   driver = dummy-ups
		   port	= evolution500.seq
		   desc	= "dummy-ups in	dummy mode"

       This file is generally named or something.seq. It
       contains	a list of all valid variables and associated values (you can
       later use upsrw only to modify values of	these variables), and has the
       same format as an upsc(8) dump (<varname>: <value>). So you can easily
       create definition files from an existing	UPS using upsc >

       It can also be empty, in	which case only	a basic	set of data is
       available: device.*, driver.*, ups.mfr, ups.model, ups.status as	filled
       by the driver itself.

       Some sample definition files are	available in the data directory	of the
       NUT source tree,	and generally in the sysconfig directory of your
       system distribution.

       Since dummy-ups will loop on reading this file, you can dynamically
       modify it with some external process to "interact" with the driver.
       This will avoid message spam into your system log files,	if you are
       using NUT default configuration.

       You can also use	the TIMER <seconds> instruction	to create scheduled
       event sequences (such files are traditionally named with	the .seq
       extension). For example,	the following sequence will loop on switching
       ups.status between "OL",	"OB" and "OB LB" every minute:

	   ups.status: OL
	   TIMER 60
	   ups.status: OB
	   TIMER 60
	   ups.status: OB LB
	   TIMER 60

       It is wise to end the script with a TIMER keyword. Otherwise dummy-ups
       will directly go	back to	the beginning of the file and, in particular,
       forget any values you could have	just set with upsrw.

       Note that to avoid CPU overload with an infinite	loop, the driver
       "sleeps"	a bit between file-reading cycles (currently this delay	is
       hardcoded to one	second), independently of (and/or in addition to) any
       TIMER keywords.

   Repeater Mode
       In this context,	port in	the ups.conf block is the name of a remote
       UPS, using the NUT format, i.e.:


       For instance:

		   driver = dummy-ups
		   port	= ups1@remotehost
		   desc	= "dummy-ups in	repeater mode"

       Unlike UPS specifications in the	rest of	NUT, the @hostname portion is
       not optional - it is the	@ character which enables Repeater Mode. To
       refer to	an UPS on the same host	as dummy-ups, use port =

       Note that to avoid CPU overload with an infinite	loop, the driver
       "sleeps"	a bit between data-requesting cycles (currently	this delay is
       hardcoded to one	second), so propagation	of data	updates	available to a
       remote upsd may lag by this much.

       Once the	driver is loaded in dummy mode,	you can	change any variables,
       except those of the driver.* and	server.* collections. You can do this
       by either editing the definition	file, or use the upsrw(1) and
       upscmd(1) commands.

       Note that in simulation mode, new variables can be added	on the fly,
       but only	by adding these	to the definition file (and waiting for	it to
       be re-read). Conversely,	if you need to remove variable (such as
       transient ones, like ups.alarm),	simply update these by setting an
       empty value. As a result, they will get removed from the	data.

       In repeater mode, the driver acts according to the capabilities of the
       UPS, and	so supports the	same instant commands and settable values.

       Dummy Mode was originally written in one	evening	to replace the
       previous	dummycons testing driver, which	was too	limited, and required
       a terminal for interaction.

       dummy-ups is useful for NUT client development, and other testing

       It also helps the NUT Quality Assurance effort, by automating some
       tests on	the NUT	framework.

       It now offers a repeater	mode. This will	help in	building the Meta UPS
       approach, which allows one to build a virtual device, composed of
       several other devices (either UPS, PDUs).

       Instant commands	are not	yet supported in Dummy Mode, and data need
       name/value checking enforcement,	as well	as boundaries or enumeration

       Arnaud Quette

       upscmd(1), upsrw(1), ups.conf(5), nutupsdrv(8)

   Internet Resources:
       The NUT (Network	UPS Tools) home	page:

Network	UPS Tools 2.7.4.	  03/01/2021			  DUMMY-UPS(8)


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