[En-Nut-Discussion] Power Strip Program

Dan Morphis dan.morphis at gmail.com
Sat Mar 4 17:56:09 CET 2006


Mark,
  I believe APC already has a product which does this on the market.

-dan

On 3/3/06, Mark J Elkins <mje at posix.co.za> wrote:
>
> I'm going to send out my idea anyway. I'm interested as to whether
> anyone has done what I'm proposing. I'm intending to make this an Open
> Source project.
>
> The Feedback I'm looking from from this list is:-
>
> Anyone done anything similar? (share?)
>
> Will the EtherNut be suitable - or should I look for a different
> platform?
>
> I'd like to think that ISP's and companies who house multiple machines
> in multiple cabinets would be interested in such a project
>
> Any other reactions?
>
> =========================================================================
>
>             IPS - Intelligent Power Strip
>             -----------------------------
>
> Scenario: The Dark Office at an ISP (an unmanned office)
>
> A room full of cabinets - each cabinet holding up to twelve Internet
> servers.  Each cabinet is self contained in that there is a UPS and a
> Switch.  The cabinet thus has two connections to the outside world, an
> UTP Ethernet connection to a central concentrator and a Power Cable
> from the UPS to its own floor socket - leading to its own circuit
> breaker mounted in a traditional electrical distribution box.  The
> circuit breakers are rated at 20Amps.  There is no Earth Leakage (bad
> idea with UPS's and Computers).  The Electrical Distribution box runs
> to a 30KVA diesel generator kit and then on to Grid power.
>
> The cabinets contain machines.  The primary requirement of any machine
> is that it can fit in the 19 inch wide cabinet.  Usually these
> machines are successfully managed remotely by their owners thus visits
> to the dark room are few.  The Machines get their power from a power
> strip running from the top to the bottom of the cabinet which is in
> turn plugged into the UPS.
>
> The primary reason for physical intervention are:-
>
> 1. The machine software goes faulty and needs to be hard rebooted
>    (usually the machine is running Microsoft windows)
>
> 2. The machines power supply goes faulty - and shorts.  The UPS will
>    remove its protection and the trip switch will trip.  This results
>    in the whole cabinet loosing power.
>
> 3. The machines fans stop turning - things overheat and eventually the
>    smoke comes out.
>
> The reactions normally consist of:-
>
> 1. The owner first checks reachability of his machine.  He then calls
>    the support desk to see if anyone else is in the dark room.
>    Ultimately, there is a car journey to simply toggle the power off
>    and on again.
>
> 2. Up to twelve clients jump on the phone to the Support Desk at the
>    same time.  Support Staff jump into a car and drive through to the
>    dark room - locate and disconnect the faulty machine, restart all
>    the other machine then contact the dead machines owner..
>
> 3. Usually the smell of smoke is detected by a neighbour.  The building
>    security calls the Support Desk and everyone runs (some to the
>    problem - some away)
>
>
>
> Solution (How)
>
> Introduce the Intelligent Power Strip. (IPS)
>
> Socket Control: The IPS can selectively remove and re-apply power to
>     any one of its twelve sockets.  It can be controlled both locally
>     and remotely.  Each socket has a (normally closed) relay to
>     interrupt supply to that socket.  Remote control could be by a
>     SNMP (Simple Network Management Protocol) command to the IPS's
>     control unit, initiated via a Web Page interface.  Local control
>     could be by some simple push buttons and a character based LCD
>     screen.  It would be useful if the power status of each socket
>     could be indicated.  This could be as simple as a Red LED across
>     the coil of the relay (i.e. it would light up in a POWER OFF
>     state)
>
> Load Detection: The IPS monitors the current load on each socket.
>     Each socket has a "Usual" value associated with it.  For unused
>     sockets, this is set to a reasonably high default.  Once the
>     equipment has settled, the "Usual" value can be automatically set.
>     Consequently, if the usual value is breached by more than an
>     additional 50%, the IPS can remove power to that socket.  The
>     "Soft Fuse" may allow for start-up loads greater than 50% - for a
>     specific time interval - i.e. when switching on a server, the
>     initial spinning up of disk drives consumes more power.  Thought
>     needs to be given to machines with multiple supplies from multiple
>     locations - which may not be under the control of the local IPS.
>
> UPS Management: The IPS can monitor and partially control the UPS.
>     Most UPS's have Serial based (RS232) management ports.  These
>     ports can provide information such as the current load status
>     (Mains ON, Mains OFF), remaining battery time left, Current Load
>     (Amps) and various voltages (i.e.  Mains condition, Battery
>     condition).  Its possible to initiate commands - such as "Switch
>     Off" - but experience shows this is a bad thing to do - except in
>     an emergency (fire?).  The UPS Management system needs to
>     understand multiple types of UPS and perhaps have an option of
>     providing custom commands for unknown models of UPS's.  Up to two
>     UPS's can be managed.
>
> Environmental Conditions: The IPS should also monitor a few other
>     conditions.
>     These include:-
>         * The total current consumption from the UPS(s) (compare with
>           what the UPS(s) states).
>         * The Temperature of the air in the cabinet (top & bottom).
>         * Smoke (fire) Detection.
>     If either smoke is detected or the temperature rises above a
>     certain value, the IPS can switch off all machines and perhaps
>     also the UPS(s).
>
>
> The CONTROL BOX would have a "local interface" attached to its front.
> The box would be mounted on the inside of the cabinet in such a way as
> to not consume usable space for servers - ie it should not be rack
> mounted.  The case size should not need to be larger than about 100mm
> square and 50mm deep.  Optionally - it could be a 1U, full width unit
> if mounted in front of the Ethernet Switch (the switch facing the rear
> of the cabinet).  Connection to the power strip would be via a
> suitable multi-core cable and connector.  There will be a separate
> cables for the RS232 interfaces between the Control Box and the
> UPS(s).  The AVR controller has a second RS232 port - which could be
> wired for a second (redundant) UPS.  There will be a standard UTP
> socket for connecting the Control Box to the Ethernet switch mounted
> in the cabinet.
>
> The POWER STRIP will have at least twelve sockets with an additional
> Euro Socket at the top for powering the cabinet fans.  The Sockets
> will be those used in South Africa (3 round pins).  The sockets and
> mains voltage could be different for different markets.  Typically,
> there will be a Euro Plug at the bottom of the strip for a connection
> to the UPS.  There will be a "normally closed" relay per machine
> socket.  There will be a Red LED per relay showing that the relay is
> now Open (the "unusual" state).  If any relay is open, the Red LED on
> the front panel display should also come on.  Each Power and Euro
> socket will have a current measuring device to enable the current for
> all devices to be calculated (total input current from the UPS, each
> machine socket and the fan socket).  This could be as simple as a very
> low valued resistor in series with the supply, with a "sensor" wire
> from the load side and a single common wire from the supply side -
> although this would result in high voltages being present in the
> control box.  **** Of everything in this document - this is the only
> area in which I am personally not sure how to proceed.****
>
> The Power strip should have a (selectable 120/240 voltage) power
> supply (transformer) to provide power to the control box and for the
> relay coils.  The power supply would need to be strong enough to
> operate all relays at the same time.  The current consumption of the
> Control Box will probably be very low.  There may be more than twelve
> power sockets in order to power the Ethernet Switch and other similar
> devices that do not need to be monitored and controlled.  The mains
> voltage (and frequency?) should also be measured and monitored.
>
> It is possible for other variations on the Power Strip, i.e.  to have
> two separate supplies from two different UPS and to have alternate
> power sockets supplied alternatively from the two power supplies.
> This would allow for machines with multiple supplies to have redundant
> power sources from more than one UPS.  In this case, the power supply
> for the Control Box should be able to take power from either or both
> sources - and report the failure of a UPS.
>
> Temperature and Smoke detectors could either plug into the Control Box
> to allow the sensors to be suitably located (near the top of the
> cabinet) or be fitted to the outside of the Control Box case.  A
> second Temperature sensor could be mounted near the floor of the
> cabinet.  As Hot air rises - this would provide a difference between
> the cooling air entering at the bottom against warm air at the top of
> the cabinet.  It would be interesting to monitor the air warming
> factor against the power used in the cabinet.  Local Interface
>
> The local interface (front panel display) could consist of:
> * A character based 4 rows by 20 character LCD display with back-light
>   (Hitachi HD44780)
> * Green "power" LED (Flashing = No network connection)
> * Red "Alarm" LED (ON = user initiated, Flashing + buzzer = self
>   initiated) Buzzer
> * 4 button input
>
>
> The Red LED and buzzer is to attract attention to a problem, the
> buzzer on entry to the cabinets vicinity and the LED to the cabinet in
> question (imagine a typical computer room with rows of cabinets).  The
> buzzer can be silenced by acknowledging the fault.  The Green LED
> gives a simple and quick status view that the unit is functioning
> correctly and connected to the Internet (it has obtained a valid date
> and time).  The four buttons could be used to initialise/install the
> unit (i.e.  Entering an IP address for the unit) as well as general
> status and control purposes.  The LCD display can provide feedback and
> status information - i.e.  the current IP address of the unit, the
> temperature and/or date and time.
>
>
> "Remote" Interfacing
>
> Via the Ethernet interface, numerous methods of control become possible.
>
> Device set-up could be as simple as a fixed, non-routable IP address
> (i.e.  192.168.0.1) which could be altered via a simple web interface.
> A more clever approach would be for the Control Box to run DHCP and
> actively fetch an IP address.  Again, a simple web interface should be
> provided in order to select a final IP address.
>
> Interrogation and control of the Control Box could be solely done by
> SNMP (Simple Network Management Protocol) including fixing IP
> addresses but a web interface is almost certainly easier for people to
> administer with.  A web interface need not be "pretty" (images are not
> desired!) but must be functional and work under any web browser (even
> text based).  An alternative way of configuring the Control Box could
> be by up/down-loading configuration files using TFTP.  Being able to
> fetch the current date and time via SNTP makes good sense (and to be
> able to display the time on the LCD display as well as for e-mail
> messages).  In order to notify people when something has gone wrong,
> the Control Box should be able to send out e-mail messages using the
> SMTP protocol.  There is no need to receive e-mail.  Simple DNS
> services may be needed.
>
>                              -oOo-
>
>
> --
>   .  .     ___. .__      Posix Systems - Sth Africa.  e.164 VOIP ready
> /| /|       / /__       mje at posix.co.za  -  Mark J Elkins, Cisco CCIE
> / |/ |ARK \_/ /__ LKINS  Tel: +27 12 807 0590  Cell: +27 82 601 0496
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