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docs/outlets.txt

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+NUT outlets management and PDU notes
+====================================
+
+NUT supports advanced outlets management for any kind of device that proposes
+it. This chapter introduces how to manage outlets in general, and how to take
+advantage of the provided features.
+
+Introduction
+------------
+
+Outlets are the core of Power Distribution Units. They allow you to turn on,
+turn off or cycle the load on each outlet.
+
+Some UPS models also provide manageable outlets (Eaton, MGE, Powerware,
+Tripplite, ...) that help save power in various ways, and manage loads more
+intelligently.
+
+Finally, some devices can be managed in a PDU-like way. Consider blade systems:
+the blade chassis can be controlled remotely to turn on, turn off or
+cycle the power on individual blade servers.
+
+NUT allows you to control all these devices!
+
+
+NUT outlet data collection
+--------------------------
+
+NUT provides a complete and uniform integration of outlets related data,
+through the 'outlet' collection.
+
+First, there is a special outlet, called 'main outlet'.
+You can access it through 'outlet.{id, desc, ...}' without any index.
+
+Any modification through the 'main outlet' will affect *all* outlets.
+For example, calling the command 'outlet.load.cycle' will cycle all outlets.
+
+Next, outlets index starts from *1*. Index '0' is implicitly reserved to
+the 'main outlet'. So the first outlet is 'outlet.1.*'.
+
+For a complete list of outlet data and commands, refer to the
+<<nut-names,NUT command and variable naming scheme>>.
+
+An example upsc output (data/epdu-managed.dev) is available in the source
+archive.
+
+NOTE: The variables supported depend on the exact device type. 
+
+
+Outlets on PDU
+--------------
+
+Smart Power Distribution Units provide at least various meters, related to
+current, power and voltage.
+
+Some more advanced devices also provide control through the 'load.off',
+'load.on' and 'load.cycle' commands.
+
+Outlets on UPS
+--------------
+
+Some advanced Uninterruptible Power Supplies provide smart outlet management.
+
+This allows to program a limited backup time to non-critical loads in order
+to keep the maximum of the battery reserve for critical equipment.
+
+This also allows the same remote electrical management of devices provided
+by PDUs, which can be very interesting in Data Centers.
+
+For example, on small setup, you can plug printers, USB devices, hubs, (...)
+into managed outlets. Depending on your UPS's capabilities, you will be able to
+turn off those loads:
+
+- after some minutes of back-up time using 'outlet.n.delay.start',
+- when reaching a percentage battery charge using
+'outlet.n.autoswitch.charge.low'.
+
+This will ensure a maximum runtime for the computer.
+
+On bigger systems, with bigger UPSs, this is the same thing with servers
+instead of small devices.
+
+NOTE: If you need the scheduling function and your device doesn't support
+it, you can still use
+<<Advanced_usage_scheduling_notes,NUT scheduling features>>.
+
+WARNING: don't plug the UPS's communication cable (USB or network) on a managed outlet.
+Otherwise, all computers will be stopped as soon as the communication is lost.
+
+Other type of devices
+---------------------
+
+As mentioned in the introduction, some other devices can be considered and managed like
+PDUs. This is the case in most blade systems, where the blade chassis offers
+power management services.
+
+This way, you can control remotely each blade server as if it were a PDU
+outlet.
+
+This category of devices is generally called Remote Power Controls - RPC in NUT.