GENERICUPS(8) Network UPS Tools (NUT) GENERICUPS(8)
genericups - Driver for contact-closure UPS equipment
This man page only documents the specific features of the genericups driver. For informa-
tion about the core driver, see nutupsdrv(8).
This driver supports hardware from many different manufacturers as it only uses the very
simplest of signaling schemes. Contact closure refers to a kind of interface where basic
high/low signals are provided to indicate status. This kind of UPS can only report line
power and battery status.
This means that you will get "MFR", "MODEL", and "STATUS". That's it. Anything else
requires a smarter UPS.
Cabling is different for every kind of UPS. See the table below for information on what
is known to work with a given UPS type.
This driver supports the following settings in the ups.conf(5):
Required. Configures the driver for a specific kind of UPS. See the UPS Types
section below for more information on which entries are available.
Optional. The very nature of a generic UPS driver sometimes means that the stock
manufacturer data has no relation to the actual hardware that is attached. With
the mfr setting, you can change the value that is seen by clients that monitor this
Optional. This is like mfr above, but it overrides the model string instead.
The essence of a UPS definition in this driver is how it uses the serial lines that are
available. These are the abbreviations you will see below:
OL - On line (no power failure) (opposite of OB - on battery)
LB - Low battery
SD - Shutdown load
CP - Cable power (must be present for cable to have valid reading)
CTS - Clear to Send. Received from the UPS.
RTS - Ready to Send. Sent by the PC.
DCD - Data Carrier Detect. Received from the UPS.
RNG - Ring indicate. Received from the UPS.
DTR - Data Terminal Ready. Sent by the PC.
ST - Send a BREAK on the transmit data line
A - in front of a signal name (like -RNG) means that the indicated condition is signaled
with an active low signal. For example, [LB=-RNG] means the battery is low when the ring
indicate line goes low, and that the battery is OK when that line is held high.
0 = UPSonic LAN Saver 600
[CP=DTR+RTS] [OL=-CTS] [LB=DCD] [SD=DTR]
1 = APC Back-UPS/Back-UPS Pro/Smart-UPS with 940-0095A/C cable
[CP=DTR] [OL=-RNG] [LB=DCD] [SD=RTS]
2 = APC Back-UPS/Back-UPS Pro/Smart-UPS with 940-0020B cable
[CP=RTS] [OL=-CTS] [LB=DCD] [SD=DTR+RTS]
3 = PowerTech Comp1000 with DTR cable power
[CP=DTR] [OL=CTS] [LB=DCD] [SD=DTR+RTS]
4 = Generic RUPS Model
[CP=RTS] [OL=CTS] [LB=-DCD] [SD=-RTS]
5 = Tripp Lite UPS with Lan2.2 interface (black 73-0844 cable)
[CP=DTR] [OL=CTS] [LB=-DCD] [SD=DTR+RTS]
6 = Best Patriot with INT51 cable
[CP=RTS] [OL=CTS] [LB=-DVD] [SD=DTR]
7 = CyberPower Power99
also Upsonic Power Guardian PG-500
[CP=RTS] [OL=CTS] [LB=-DCD] [SD=DTR]
8 = Nitram Elite 500
[CP=DTR] [OL=CTS] [LB=-DCD] [SD=???]
9 = APC Back-UPS/Back-UPS Pro/Smart-UPS with 940-0023A cable
[CP=none] [OL=-DCD] [LB=CTS] [SD=RTS]
10 = Victron Lite with crack cable
[CP=RTS] [OL=CTS] [LB=-DCD] [SD=DTR]
11 = Powerware 3115
[CP=DTR] [OL=-CTS] [LB=-DCD] [SD=ST]
12 = APC Back-UPS Office with 940-0119A cable
[CP=RTS] [OL=-CTS] [LB=DCD] [SD=DTR]
13 = RPT Repoteck RPT-800A/RPT-162A
[CP=DTR+RTS] [OL=DCD] [LB=-CTS] [SD=ST]
14 = Online P-series
[CP=DTR] [OL=DCD] [LB=-CTS] [SD=RTS]
15 = Powerware 5119
[CP=DTR] [OL=CTS] [LB=-DCD] [SD=ST]
16 = Nitram Elite 2002
[CP=DTR+RTS] [OL=CTS] [LB=-DCD] [SD=???]
17 = PowerKinetics 9001
[CP=DTR] [OL=CTS] [LB=DCD] [SD=???]
18 = TrippLite Omni 450LAN with Martin's cabling
[CP=DTR] [OL=CTS] [LB=DCD] [SD=none]
Many different UPS companies make models with similar interfaces. The RUPS cable seems to
be especially popular in the "power strip" variety of UPS found in office supply stores.
If your UPS works with an entry in the table above, but the model or manufacturer informa-
tion don't match, don't despair. You can fix that easily by using the mfr and model vari-
ables documented above in your ups.conf(5).
If your UPS isn't listed above, you can try going through the list until you find one that
works. There is a lot of cable and interface reuse in the UPS world, and you may find a
To do this, first make sure nothing important is plugged into the outlets on the UPS, as
you may inadvertently switch it off. Definitely make sure that the computer you're using
is not plugged into that UPS. Plug in something small like a lamp so you know when power
is being supplied to the outlets.
Now, you can either attempt to make an educated guess based on the documentation your man-
ufacturer has provided (if any), or just start going down the list.
Pick a driver to try from the list (genericups -h) and go to step 2.
Start the driver with the type you want to try -
genericups -x upstype=n /dev/port
Let upsd sync up (watch the syslog), and then run upsc to see what it found. If the STA-
TUS is right (should be OL for on line), go to step 3, otherwise go back to step 1.
Disconnect the UPS from the wall/mains power. This is easiest if you have a switched out-
let in between it and the wall, but you can also just pull the plug to test. The lamp
should stay lit, and the status should switch to "OB". If the lamp went out or the status
didn't go to "OB" within about 15 seconds, go to step 1. Otherwise, continue to step 4.
At this point, we know that OL and OB work. If nothing else beyond this point works, you
at least know what your OL/OB value should be.
Wait for the UPS to start complaining about a low battery. Depending on the size of your
UPS battery and the lamp's bulb, this could take awhile. It should start complaining
audibly at some point. When this happens, STATUS should show "OB LB" within 15 seconds.
If not, go to step 1, otherwise continue to step 5.
So far: OL works, OB works, and LB works.
With the UPS running on battery, run the genericups driver with the -k switch to shut it
genericups -x upstype=n -k /dev/port
If the UPS turns off the lamp, you're done. At this point, you have verified that the
shutdown sequence actually does what you want. You can start using the genericups driver
with this type number for normal operations.
You should use your findings to add a section to your ups.conf. Here is a quick example:
driver = genericups
port = /dev/ttyS0
upstype = 1
Change the port and upstype values to match your system.
If the above testing sequence fails, you will probably need to create a new entry to sup-
port your hardware. All UPS types are determined from the table in the genericups.h file
in the source tree.
On a standard 9 pin serial port, there are 6 lines that are used as the standard
"high/low" signal levels. 4 of them are incoming (to the PC, from the UPS), and the other
2 are outgoing (to the UPS, from the PC). The other 3 are the receive/transmit lines and
Be aware that many manufacturers remap pins within the cable. If you have any doubts, a
quick check with a multimeter should confirm whether the cable is straight-through or not.
Another thing to keep in mind is that some cables have electronics in them to do special
things. Some have resistors and transistors on board to change behavior depending on
what's being supplied by the PC.
SPECIFIC MODEL NOTES
These have been contributed by users of this driver.
The Centralion CL series may power down the load if the driver starts up with the UPS run-
ning on battery as the default line settings contain the shutdown sequence. - Neil Muller
The Tripp-Lite Internet Office 700 must be used with the black 73-0844 cable instead of
the gray 73-0743 cable. This entry should work with any of their models with the Lan 2.2
interface - see the sticker by the DB9 connector on the UPS. - Stephen Brown
Type 5 should work with the Tripp-Lite Lan 2.1 interface and the 73-0724 cable. This was
tested with the OmniSmart 675 PNP on Red Hat 7.2. - Q Giese
Types 7 and 10 should both work with the PhoenixTec A1000.
There is no way to reliably detect a contact-closure UPS. This means the driver will
start up happily even if no UPS is detected. It also means that if the connection between
the UPS and computer is interrupted, you may not be able to sense this in software.
Most contact-closure UPSes will not power down the load if the line power is present.
This can create a race when using slave upsmon(8) systems. See the upsmon(8) man page for
The solution to both of these problems is to upgrade to a smart protocol UPS of some kind
that allows detection and proper load cycling on command.
The core driver:
The NUT (Network UPS Tools) home page: http://www.exploits.org/nut/
NUT mailing list archives and information: http://lists.exploits.org/
Tue Oct 15 2002 GENERICUPS(8)