Topic: Is there any interest in a hardware board which will allow remote power cycling (Read 19560 times)

Three more here!

In exchange, I promise you fresh baked shiny Bitcoins. 

I'd be interested as well. I'd need three of these units.

Any way I can talk you into a couple?  Or at least one?

Thanks but I already have a power cycling board for 8 rigs.  There wasn't enough interest for me to try and mass produce the boards.

I was thinking of making a finished project to sell (maybe parallel port control in a gutted UPS, since they have outlets and a breaker), but I decided to just sell my solid state relays for your projects here cheap:
https://bitcointalksearch.org/topic/wts-solid-state-relays-120v-power-switching-76678

Video fun: http://www.youtube.com/watch?v=_-UB5mhac_g

I'm in for 1.  Down to 3 rigs now so either the $100 or $75 version is fine.

I think what you have will work fine. The only reason I mentioned solid state relays is because they are reliable (no moving parts) and shouldn't require additional components such as caps. Anyways, the holding the power button option sounds sufficient for this application.

The length of time can be customized.  I have never had a failed rig not power cycle when holding down power button although I guess it can happen.

Not sure what you are asking about solid state relays.  They tend to be even more expensive but aren't necessary for this application.

For direct power switching the additional cost comes from the requires of switching 15A @ 120V/240V vs <1A @ 5V.
a) receptacles & housing
b) higher gauge wire
c) higher current relays

So we are looking at more like $200 per unit.  Seems like a lot more cost and complexity for not much gain.

So if I understand correctly, you have modified the design specs so that the relay now holds down the power button for ~4 sec to kill the box, instead of switching the power? If so, what about +5VSB which stays on regardless? It may need to also be switched off in order to completely reset poorly designed boards.

Also, yes power switching is a bit more complicated, but I wonder how much extra solid state relays would cost. They do require some current to stay on however, but I don't know how much.

I got a PM asking about a smaller board.  Really smaller boards don't save much cost but if there is enough interest I could do a 4 port version for <=$75 (exact price will depend on bulk purchasing).

Nothing as long as you are running on 240V and all your rigs combined used less than 2.4KW.
There is also nothing wrong with the PDU that giga linked to.  Switched PDUs rock.  I was so glad in my last job when our company stopped being cheap and upgraded to switched PDUs.  Click-click reboot crashed server.  Their only downside is the cost per watt is pretty high as they tend to be designed for dense racks, so they have more ports and less wattage than we need.

If I could find a switched PDU that had:
* 30A input (24A usable) @ 240V
* NEMA L6-30P plug
* At least 6 C14 plugs
* <$200
I wouldn't have even started this thread. I would have bought it last year.  The only problem is .... it doesn't exist.


I guess one way to look at it would be a new spec:  "$ per KW switched".

The PDU giga linked to:  20@ at 240V = 4.8KW.  $450 / 4.8KW = $93.75 per KW
The PDU you linked to:  10@ @ 240V = 2.4KW. $130 / 2.4KW = $54.15 per KW
The best used PDU I have found on ebay:  30@ 240V = 7.2KW.  $600 / 7.2 KW = $83.33 per KW

USB board efficiency would depend on how many rigs and how much wattage:
USB relay board powering 6 1000W rigs.  6*1000 = 6.0KW.  $100 / 6.0KW = $16.67 per KW
USB relay board powering 8 1200W rigs.  8*1200 = 9.6KW.  $100 / 9.6KW =  $10.41 per KW
Mini USB relay board powering 4 1000W rigs.  4*1000 = 4.0KW.  $75 / 4.0KW = $18.75 per KW

Far right drop down has English.   There you go.....

If I could read that web page, I might be interested.

What's wrong with something like this? (I think about purchasing one)

http://www.reichelt.de/?ACTION=3;ARTICLE=102254;GROUPID=4308;PROVID=2351;&utm_source=Preisvergleich&utm_medium=CPC&utm_campaign=Preisvergleich_preisroboter.de#av_tabdata

~ 130 USD, max. current 10A

Ok... in either case, it's better than most alternatives, so I'm definitely in for 2.

Yes.  Any machine with USB connectivity and capable of either windows or linux would be fine.  I would recommend it not being a mining rig for maximum reliability.   I am using a barebones machine which hosts p2pool and bitcoind as well as running ANUBIS for monitoring.

I looked into ethernet boards but they were more expensive and that still requires some software running somewhere to do automated reboots.

I'm down for at least 2 of them.  However, can you reiterate what is hosting this?  Another machine?  Essentially, we'd have to have a barebones dedicated machine to handle this to have some reliability, right?

Some details and photos.  Sorry about not getting the photos out last night.  Wife had a bad day at work and we "solved" it by getting plastered.  

Note: the board in the photo is a higher end board with lots of ADC (measuring analog sensors), and DC power circuits.  It is much more expensive (~$200) than anyone would want for turning rigs on and off.  I bought this because I need remote sensor monitoring and out of band power control.   Still it should give people some ideas.



My goal is to use a similar lower end board with 8 2A relays and USB interface.  I scrapped serial interface idea as I found a board which doesn't have a huge premium for USB over serial.  Power is 12VDC supplied by a Molex adapter.  Each kit will include the relay board, control software (initially Windows but eventually Windows & Linux) and wiring adapters for power control.



The power control adapter connects to the ATX header on the motherboard.  It is connected to the power switch not reset pins.

Why switch power at the motherboard and not from the wall?  Cost and safety.  To handle full rig current would require using 10A relays and inductive capacitor which add about $20 in cost.  Honestly even that is risky.  Pulling >1200W could burn the relay and possibly the usb controller.  Worse if voltage sags (which can happen) then current rises.  1100W on a 102V circuit is >10A.  So to be safe under all conditions 15A/20A relays would be better and that adds about $40.

Switching low voltage DC is safer and easier.  Worst case scenario if relay fails in open or closed posistion it is no different than either not pushing or continually pushing the power button on your computer.  Failures are "clean" and safe.  Motherboards and ATX PSU already have the expensive relays and safety circuitry built in so why not use it.

I tested it with leads as long as 6 feet and switching is reliable.  I did 20 on off cycles and had no failed trips.  I can test it for longer leads is there is need.    Essentially the relay is no different than pressing and holding the power switch.

Configuration requires a little testing.  I found it takes 1200 msec to power on rig, and 4000 msec to power off the rig.  A nice feature is that is the status of the rig is unknown keeping relay closed for 6500 msec will ensure the rig is now off.  (If it was off it will power on and then back off).  I call that "forced off".  Since the board can't know for sure if a rig is off, "forced off" can be used to put the rig in a known state.  It then can be powered on.  I imagine this will vary by motherboard but can be tested/verified by simply pressing and holding the power switch.

This afternoon after I get out of some meetings I will post some shots of the (alpha) software.

I have experience to write a windows software.  A command line and GUI application for manual control and configuration plus JSON API for extending functionality to third party applications.    I will need assistance with porting that over to Linux.  Someone has (thankfully) already PM indicating he is interested in helping on the Linux side and based on his coding experience it shouldn't be an issue.  I will let him announce it in the thread if he wants it public.

Cost will be ~$100 per kit (controls 8 rigs)
* USB relay board with eight 5A SPDT
* wiring for connectivity, power, and connections to remote rigs (plus some spares)
* open source manual control software plus API which would allow 3rd parties to write automated control (reboot on crashed GPU)
* support & troubleshooting

Update:  mini USB relay board.
If there is enough interest I can also offer a 4 rig version for $75.  Sorry less relays don't save that much but if someone knows they will never need more 4 rigs switched it might be an option.  The mini board would work exactly the same except it would have 4 not 8 5A SPDT relays.

To make this worthwhile I will need interest in at least 10 boards.  Sorry but margins are small and my time is valuable.  Not asking it as this point but before I order parts I will require a $10 pre-order deposit.  I board isn't shipped in 4 weeks (should be faster than that) or final price ends up being >$100 you can cancel and get deposit back.  If board is ready for shipping at <=$100 deposit is non-refundable (you could sell your deposit to someone else).

Thoughts, comments, questions, concerns, rants, objections?

I thought this cheapo ethernet relay board software includes an open API.

I actually got shipment for mine to US so can't fiddle around yet, but i'm sure i can whip up an easy to use interfacing layer quite fast when i do.

My thinking was to chop up the power cords and place the serial relays inline, but I can see that that would be a pain for so many machines.

In a dual PSU rig, it is only necessary to switch off the first PSU (the one that powers the motherboard), and not both, so an SPDT relay would be all that is needed. It is a good idea to use SPDT, because then you can connect the rigs across the normally closed terminal and leave the relays in the "off" position unless you want to power cycle a rig. Less wear and tear.

I have 18 rigs (*starts dreaming about 32 rigs for a second). 3 per 208v 20amp circuit. 6 take care of the GPU rigs and the computer running the singles. The other 2 are for, well, more BFL equipment.

Dual relays are pretty much useless for anyone with a farm.  I have 8 going on 12 rigs.  giga has 32 rigs.

I think he wants serial, not ethernet, and these suit perfectly: http://www.controlanything.com/Relay/Device/R220HP

24 bucks for a dual 20 amp SPDT relay board, homebrew serial. If you want 9-pin d-sub connectors, use http://www.controlanything.com/Relay/Device/R220HPRS for 10 bucks more.

If your rigs only have 1 power supply, use the single relay board for $19 each: http://www.controlanything.com/Relay/Device/R120HP or the same thing with 9-pin d-sub for $29: http://www.controlanything.com/Relay/Device/R120HPRS

If you want to mortgage the farm, they offer a 32-relay board with 20 amp SPDT relays for $933: http://www.controlanything.com/Relay/Device/ZUXPR3220PROXR_ZRS

Nothing.  One could also write their own miner or build their own pool too.  I would imagine not everyone would want to research boards, find one that is compatible, cut custom wiring harness, and code up an API.  Still there is nothing that is stopping them.

Having a common API is the reason I am interested in making a standardized board and API.  I already have a board and it gives me manual remote power control.  

However to expand beyond that I need there to be enough similar boards so that third parties look to support them via API.

Like:
* Having a cgminer monitoring program (like anubis) which reboots any rig in a farm as needed when a GPU crashes.
* Building a hearbeat into BAMT (and as a package for other linux distros) that the relay board listens for and reboots a server when its haearbeat stops.
* paying a third party to provide SMS support for the relay board so that you can get messages when a rig is rebooted.

There are advantages of having large number of people using the same hardware and software.

But you can purchase that ethernet relay board, and it's completely open, so what's the prob on using them? :O

To put this another way, I see two routes to getting remote power cycling.

Option #1 -> http://pdusdirect.com/power-distribution-units/switched/pdu-cw-8h2-c20m
Options #2 -> D&T having mercy on me with a reasonable price that he can still make good money on

With option #1, I would need at least 8.

This sounds interesting but as always the devil is in the details......

What is this going to cost to make it worth your while?

My prototype is working.  I will share some pics tonight.  I have been busy working on watercooling stuff.  The code used to drive the prototype is ugly.  I am still debating if I will commercialize it.  On one hand it likely will be a lot of work with low margins.  On the other hand if enough units are sold that will likely create the demand for third party applications to provide
support which helps me.

I'll post the photos and see what kind of feedback I get.

I think the consensus now is that http://www.ebay.com/itm/180563287252?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649 gets the job done

How's this project going?

An update:
Got my prototype working in windows.  Device is detected by Windows and I can send signals to the board via console app.

I don't have all the wiring I need to connect all 8 relays but I was able to remotely power cycle (and power off and power on) a single rig hooked to relay #0.

Is it nerdy that I smiled after pressing enter on my laptop and seeing a rig power cycle?

Hopefully the rest of wiring parts will be here by this weekend.

Yeah, i am

BTW, are you actually a (the?) guy that works at pulsedmedia.com? Great seedboxes there.

Some models have 15A relays. Not that it matters that much, as usually you have 16A fuse for a regular 230-240V line and 2.3kW is already plenty for single rig.

I bought a 16relay IP version for testing. Too cheap to pass up!

Pretty cool. Each board has two 10 amp @ 240 VAC relays, and they are SPDT which means they don't have to be on all the time. Just turn the relays on for a few seconds when you want to kill the rig. The little ethernet board works directly with SNMP for you hardcore monitoring folks.

neat.
Even better: http://www.ebay.com/itm/USB-16-CH-Relay-Switch-Module-Board-Home-Automation-12V-/180751504176?_trksid=p4340.m444&_trkparms=algo%3DPI.WATCH%252BCRX%26its%3DC%252BS%26itu%3DUCC%252BSI%252BUA%252BLM%26otn%3D15%26po%3D%26ps%3D63%26clkid%3D6788483942134694749

Each of the relays allows 15A current to pass through and upto 250V AC, or 24V DC

16 Relay IP Board:
http://www.ebay.com/itm/Internet-Ethernet-16-Relais-Platine-IP-SNMP-WEB-/180626947903?pt=Mess_Pr%C3%BCftechnik&hash=item2a0e347f3f

USB 16 relay board:
http://www.ebay.com/itm/USB-16-Channel-Relay-Board-Virtual-Port-12V-/170432366651?pt=LH_DefaultDomain_0&hash=item27ae8f883b#ht_8976wt_1396

If you need big amount of these then a AMD E350, Sheeva/Guruplug, Raspberry or something like that to control the USB versions to get you even lower in price

Ofc, utilizing these as PDUs will require a bit of wiring but oh well....
Ordering one for testing!

Check this:

http://www.ebay.com/itm/180563287252?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Il be working on remote power cycling when i get my pi, got alove gpio

I would like to buy one of this, definitively...

Sometimes, one or another mining rig just hangs... I know that cgminer is still "running" because I can access it trough its APT but, it is impossible to connect using ssh and restart my machine...

But, sometimes, I can access and reboot the mining rig using SSH and Linux Sysrq subsystem:


This works more or like pushing the reset button of the case...

Anyway, this does not works all the time, forcing me to do the regular local power cycle.

It can be awsome if cgminer can run "echo b > /proc/sysrq-trigger" trough its API... So, even if machine is "out of ssh access" but, cgminer is still running (and machine still answer ping requests), we can send a command to cgminer do the restart job...

Best!
Thiago

Well windows 7 never gives me an issue with hard reset and I know it inside and out. I can't even f'in change software in linux, so for me, it's a no brainer.

Besides, when I sell off my stuff I Will be building all the gear into gaming rigs and a super badass rig for my home theater dream set-up.

Heeeeeyyyyy..... those are expensive. You selling them?

I have about a dozen surplus solid state relays like this one in 10A and 20A. They are used for industrial control, and are sized (and priced) more for controlling an entire circuit than just one machine, but the 10A ones would be appropriate for a 1000w rig. They are off by default and need 3-32V to turn them on, so a simple parallel interface would need to hold them high, or with a 12v power supply running them with pull-down resistors, you could design a circuit that turns them off with a momentary +12V signal input to ground.



PS I have melted those little blue circuit board relays into goo before, they might say 10A, but they arc inside when they turn off, which a zero-cross solid state relay doesn't do.

If someone does an cost-effective and easy solution for hard power cycling, i would not hesitate to spend several hundred euros immediately for just testing gear

So if someone finishes that Arduino design and makes it easy to order complete units i would buy several immediately.
Even if i have to solder the 230V (110V) power cables onto the relay board wouldn't really matter.

Another thing i'm looking for is something which can switch from power source to another, say network power goes out, it changes to inverter operated from a bunch of car batteries kept charged by a cheap 40€ trickle charger.

I run into hard power cycle problems in Windows far, far more often than in Linux.  I can't remember the last time Linux gave me any issues about a hard power cycle.  Windows has certainly gotten better about it in recent years, but when something goes south, Windows usually requires a reinstall, whereas Linux requires a manual fsck and it's good to go.

I'd be interested also. I'll be building my cluster off a windows network, so this would be great since power cycles don't cause as much issue in my experience with windows as opposed to linux.

Not starting a linux war, just saying for ME, this would work great. All my machines are hard wired on an ethernet network at my house and I'll have them running through a home server or some type of RDP soon.

If I could power cycle and restart remotely that would be great.

If you use small fet's instead of relays you can cut that cost down.  If you build your own boarduino you could probably get the cost down to less than $20.

Back in July I built an arduino resetter that hooked to both reset and power.  Had feedback to show when the computer was on/off.  Temp monitoring for ambient and room temp.  I wrote the GUI to interface with a control computer (yes, parallel port would probably have been easier but I had the arduino). 

Right after I got it done I never needed it again.  I got my rigs to the stable point where they do not shut down unless the power is lost.  I was going to do an instructable but I got busy with other things. 

Arduino with relay board and ethernet shield works out to something like 275$ for around 40 ports. 160$ of which is relay boards, 8 of them.
Tho requires a bit of work to get running, but ought to be rather easy after that.
Not a perfect solution, but half way there.

D&T,

I was looking into purchasing 9 of these:

http://pdusdirect.com/power-distribution-units/switched/pdu-cw-8h2-c20m

If you can save me $350 a pop, I would buy enough for my entire farm, and future farm.

This is the last piece missing for me being able to leave town for an extended period of time.

Best,
gigavps

I've done quite a bit research on this for servers, namely how to build a cluster of cheap servers on the cheap.

One option is to use Arduino with a Relay board and Ethernet Shield.
That will give you maximum of around 40 relays, depending upon model of Arduino used etc.
Parts can be sourced from: http://arduino-direct.com and eBay
Some information: http://arduino-info.wikispaces.com/ArduinoPower#4-8

As for finished product i ended up choosing IP Power 9258T and Avocent Direct PDU for initial setups for it's low buy-in price.

For KVM i ended up choosing Belkin Omniview for larger setups and Aten CS1716i for smaller setups.
For big setups Belkin Omniview works out somewhere around 30-40$ per node, depending upon do you get your gear from cheap or expensive place.
Aten CS1716i is a few $ more expensive per node only, but the Belkin also provides saner setup by the means of using CAT5 cabling

I don't think you are talking about the same thing.  I have experienced cases where the power switch is more reliable than the reset switch at fully restoring a machine to working condition, especially when GPUs get into funny states.  I have also experienced cases where the motherboard power switch is not enough to bring the machine back up, and cutting power to the power supply is needed.  I think that happens when a safety feature in the power supply triggers as a result of some power issue.  It is rare enough that I don't worry about it--the motherboard power switch technique works well enough for me.

I've experienced this as well (particularly after a power brownout).

Now we're talking.
That's a reasonable price!

Do yourself a favor and source cables from China, for instance via Winstronics http://www.winsusa.com/ instead of soldering or crimping them
yourself.

Reset switch is not sufficient to reset some dead cards.  Only a power cycle works.  A reset watchdog board is not anything I'd be interested in as it would be completely useless in most situations where I need to remotely restart a rig.

I could make a unit with a web control panel that could be used to control up to 8 units via the mainboard power switch pins (or reset) for about $25 retail. I would use a PIC18F86J65 controlling some FETs. It would be about 2"x1" in size. I have these microcontrollers in stock and can get boards made in a couple weeks. Since I already have a similar board design done the only real additional work involved would be the code to host a web interface.

(The similar design is for my fpga miner controller posted elsewhere on the forum).

Could likely do up to 16 computers for another $5 or so. I guess making long jumper wires would be a bit fiddly though so maybe they would be extra. But I could include a small Nokia style power adapter or it could be made to plug into a molex easily enough.

Oh god yes dude! I totally support your project, and I'll be the first buyer. 

There are plenty of people on this forum that have multiple mining rigs.  Those USB switched outlets are great for a few rigs, but they'll start getting expensive (combined with the fact that you'd also start needing a USB port for each).

The OP asked if people were interested in a board.  I don't recall him asking for snide remarks.


I'd be interested in some boards if the software was right.  If we're looking for something that just hits the reset switch on the board though, they can easily be built from parts at iorelay (and they make expandable units).

You could make a little board that has a relay (or multiple relays for multiple machines) that shorts the motherboard reset switch. Make it controlled by a serial or parallel port of another machine, so you don't need high tech network hardware, just log into another always-on machine or a $20 used POS laptop and send the port the reset command.

Here's a page for making easy parallel port circuits: http://www.epanorama.net/circuits/parallel_output.html#relaycontrol

Building your own relay controlling circuits

The following circuit is the simples interface you can use to control relay from parallel port:

                             Vcc
                              |
                              +------+
                              |    __|__
                            Relay   /^\  Diode 1N4002
                             Coil  /---\
                              |      |
                              +------+
                              |
                           | / 
                 4.7K    B |/  C
parallel port >-\/\/\/\/---|        NPN Transistor: BC547A or 2N2222A
data pi                    |\  E
                           | V
                             |
parallel port >--------------+
ground pin                   |
                          Ground

Pretend I just made one, hook up your reset switch leads to each machine here:

Please realize that few, if any, people will need 8 individually switched outlets.
Thank you.

Maybe you have trouble reading so I'll help you.

So you going to buy him 8 for $200 and mark it down to $100?  Your a nice guy.

OK, PM me how many you want, I'll buy them at Amazon for $24.54 (see my previous post), mark them up to $100 and resell them to you.

I'd be in for 1 maybe 2.  Can't even count how many times I've waited days for someone to power cycle my remote rigs. 

I'd probably be in for a couple at least.

  For my remote systems, it's always nice to go issue a remote physical power-on and off reboot should something crash.  I was really thinking of how to do this aside from setting up and testing WOL.

  If a simple box / interface that is hooked up to the machine(s) could cycle them off and on remotely if necessary that'd be great. 

  I'm interested to see how this works out.  For $100 that's not bad at all to invest in.

This place makes a ton of awesome little boards and control relays that would be perfect for this. Tons of options. Have a browse through their site, you won't be disappointed at the selection.

It sounds pretty much like what I already use.  See Kit 108 on kitsrus.com.  It is a serial port controlled relay board with 8 relays.  Available assembled from sources including:

• http://www.electronickits.com/kit/complete/elec/ck1610.htm
• http://www.electronics123.com/s.nl/it.A/id.291/.f

I just had to wire it into the power switch of each machine.  I used some phone wire spliced with these power switch extension cables:

• http://www.frozencpu.com/products/1835/ele-187/FrozenCPU_Standard_Motherboard_Power_Switch_Extension_Cable.html

So yes, it's a good approach, and I would have been interested in a ready made solution with all the necessary wiring if it were available when I was looking, but I already have what I need now.

Recently, I bought such a device for $24.54 at Amazon.
It is the "USB Net Power 8800 Single Outlet Network AC Power Controller" and it has a USB cable. While intended for Windows, someone has written a Linux driver, which can be downloaded. In fact, I use it with Ubuntu Linux.

http://www.amazon.com/Power-Single-Outlet-Network-Controller/dp/B004L7NDVQ/ref=sr_1_1?ie=UTF8&qid=1330713310&sr=8-1

I use it to power-cycle my %^$#%& DSL modem, which once in a while decides to go catatonic.
I wrote a perl script which detects that the aggregate hash rate of all graphics cards on this particular rig has fallen to 0.0 MH/s, whereupon the script turns the power to the modem off for one second, then on again.
Works like a charm.

Edit: I just looked at the type plate of this device, and it says "6 Amps".
       Definitely OK for a DSL modem, but probably too lightweight for a 4-GPU or 5-GPU mining rig.

I think you are missing the point.  I am already building a control board for myself.  I have done extensive research.  Off the shelf PDU are cost prohibitive and custom networked sensors are expensive and complex.  I already have a solution for myself I am just seeing if others would be interested in a scaled down version for rebooting rigs.  I now regret putting any of that background in the first post (on edit: removed).

The purpose of the thread is to gauge interest in an out of band power control board.  I will put you down as "No. Have no use".  Thank you for keeping this on topic.

Well for me with a cooling failure the entire rig could become unresponsive and keeping it powered on without cooling is a good way to slag couple thousand worth of gear. 

So for myself having an out of band controller is simply a requirement.  One would be gambling every second that no rig would become unresponsive in a "loss of coolant" accident.   That is just an asininely stupid risk to take.  So I will be building my custom controller anyways.  I already have an "server" which has no miners and runs p2pool anyways.

Now for other users there may not be a demand.  If people never run into an unresponsive rig or a rig which hangs during reboot then there likely is no value.  That is what I am trying to gauge before I build 20 boards that nobody needs.

Background (can safely skip if TL/DR):

on edit: removed as it seems to be a distraction.

..


Remote out of band power control
There are PDU that offer ability to power cycle devices remotely but they tend to be very expensive and have insufficient wattage for a large number of rigs.  For example the unit in the link below has 16 individually switched outlets but only 5.76 KW of switchable power or about $100 per KW.  Using conventional remote power solutions is cost prohibitive. 
http://www.amazon.com/Tripp-Lite-PDUMH30HVNET-Distribution-Switching/dp/B0013HY9E2

So why not just shutdown/reboot the rig via the command line using ssh?  That certainly is a solution most of the time but the rig may be unresponsive, the mining software may hang when it tries to shutdown with crashed GPUs, or rig may hang during reboot.

An analog power switch is essentially fool proof.  Power rig off, wait, power rig on.  It can't be defeated by failing software on the mining rig. I am gauging interest (no guarantees, no pre-orders, no timelines just gauging interest) for a control board which would provide remote out of band power control for multiple mining rigs.

Tentative simplified board specs:

• Requires a host "server" (any non mining computer) with an RS-232 port (USB to RS-232 adapters are available for ~$10)
• Can physically power on, power off, and power cycle up to 8 rigs (multiple boards could be used to control more rigs)
• Linux and windows OS supported.
• Will expose an API for integration into existing or custom applications (like hypothetically ANUBIS)

Cost: ~$100 (rough estimate)