Wake-on-Lan

Has anyone created a RISC OS WOL tool that I could use to wake up a remotely sited NAS? (on the same LAN, but a different building.)

I’m asking before trying to do it myself.

Edit: Should have googled first. Now found Dave Higton’s program.

Hi Alan,
I do, I made one long ago, let me find the sources and I’ll put them in the RISC OS Community repo on github.

Do you have GCC or DDE, if none I’ll pre-compile it for you. (works best if compiled with GCC, DDE had some issues with their ported libraries IIRC).

P.S.
NEEDS TO BE TESTED, I haven’t used it in a very long time, no idea if it still works.

Yes – I have been using !Wakeup to start my Synology NAS for years, and it works very well – especially as I usually run it from an Organizer Task alarm.
It is by Dave Higton (as you have now found, I see).

@ Martin

If Dave’s one is proven to be working then I suggest to use that one.

I’ll still upload my sources in the github repo, so everyone who wants to improve my code or test it can play with it and we’ll have shared sources that are always better than just binary, given we are all ageing here XD

Mine works for machines whose Ethernet interfaces respond to “magic packets”. Just remember never to remove mains from the machine. It fooled me for ages when I was testing it…

The OS needs to run in order to set the interface up to respond. Removing mains makes it forget until the OS runs again. So soft power down only!

Has anyone created a RISC OS WOL tool that I could use to wake up a remotely sited NAS? (on the same LAN, but a different building.)

Same subnet, or routed subnets?
If it isn’t the same subnet you need some kind of forwarding of the magic packet on the IP interface of the router. The packets are broadcast, and all sensible network techies don’t enable broadcast forwarding.

The OS needs to run in order to set the interface up to respond. Removing mains makes it forget until the OS runs again. So soft power down only!

Most NICs it’s a saved setting in the card. Common as muck Intel stuff certainly, Cisco and HP too.
No power on the NIC at the time of WoL attempt is a non-starter of course.

In my case, it’s a Synology NAS set to hibernate then power down. The power supply is external, and will remain on. I’ll see what happens if I power that down, then on again. I expect WOL will still work, but needs testing.

There’s no subnets – just a wire between buildings.

I’ve still to investigate how to wake it up from Windows. It takes around 90 seconds so I need a way for the Windows bit to wait for a response.

I use mc-wol by MatCode from Win10 – is is only 6kb, but it is only command line, but works fine for my use from a desktop shortcut.

I use mc-wol by MatCode from Win10

Thanks. There are a number of options. The tricky bit is more about issuing that command then waiting until the NAS has powered up, which is in the order of 90 seconds. I could tackle that by scheduling two jobs a few minutes apart, or delve into the depths of PowerShell, whuch seems to have something resembling wait commands.

The aim is to have this kick off automatically, and it’s the same aim for RISC OS too. That’s closer to working right now.

There’s no subnets – just a wire between buildings.

Same ground and electrical phase in both?
I’d be inclined to use fibre – tend not to get any electrical conduction on that :)

I’ve still to investigate how to wake it up from Windows. It takes around 90 seconds so I need a way for the Windows bit to wait for a response.

Various scripting utilities around for that.
Perl has “Expect” to check for specific response

AutoIT has stuff to look at window content and react to that.

Same ground and electrical phase in both?

The machine room where I used to work had the machines split between three phases, with red, yellow and blue tape marking the areas; there were strict instructions not to connect anything between machines on different phases.

This conveniently ignored the fact that all the machines were connected to Ethernet switches regardless of phase.

There really isn’t a problem interconnecting machines on different phases with Ethernet cables. The simple requirement is that all the machines have a good connection to earth. There is no point whatsoever in argiung about different earths – the previous sentence gives the full specification.

Ethernet interfaces are all insulated by transformers unless power over Ethernet is involved, and computers don’t normally supply or consume PoE.

It is a common supply, i.e. from the same incoming board. It’s a (just) detached garage.

We also had fun at work, when we first installed 10base2 cable – remember those? The site had two substations. When we got strange errors I disconnected the cable at one end and put a multimeter between the earth of the cable and the connector. 50VAC.

We now had the ammunition to get permission to install optical fibre.

Incidentally tests on the NAS show that if it powers itself down, then the mains is disconnected and reconnected, it responds to WOL. If on the other hand I power it down using the button, after mains power is restored it doesn’t respond to WOL.

So it does what I want in respect of power cuts.

The simple requirement is that all the machines have a good connection to earth.

One comment – Victorian hospital buildings¹, with electrical supply with spikes that destroy UPS units.

¹ We have more than one decent size site. The service territory seems to be growing too

Incidentally tests on the NAS show that if it powers itself down, then the mains is disconnected and reconnected, it responds to WOL.

WoL, power scheduling and auto restart (after power interruption) are interlinked.

One comment – Victorian hospital buildings, with electrical supply with spikes that destroy UPS units.

Spikes that destroy power supplies of any kind are nothing to do with earth connection, unless the earth connection is completely missing, in which case your overriding consideration should be the safety of all your staff. I’ve seen power supplies destroyed as a result of a loose neutral connection in a three phase box, which resulted in our neutral voltage being significantly different from zero, depending on what was being consumed from the other two phases, so what should have been supplied to us as 240 volts was often a lot more.

Other than that, if there are heavy loads being disconnected abruptly, there can be brief spikes. Stuff that is designed to modern EMC specifications should be immune. Maybe you’ve got old equipment, or stuff that claims to be conformant with standards but isn’t really. (Our building security system suffered several PSU failures on brown-outs. That was elementary bad design.)

Or maybe your mains system has some fault such as a loose neutral as I described above.

There is mains monitoring equipment out there for purchase or rental – it might help you diagnose what’s wrong.

When we got strange errors I disconnected the cable at one end and put a multimeter between the earth of the cable and the connector. 50VAC.

One end, at least, wasn’t earthed.

Something else to consider is that your earth connection isn’t supplied to you from the substation – it’s entirely local to your premises. In the old days of lead or copper water pipes, they were a gift in that they were large areas of metal in contact with the earth, and you could easily make a good electrical connection to the rising main. If the pipe has been replaced with plastic, you could have lost the earth connection.

Something else to consider is that your earth connection isn’t supplied to you from the substation – it’s entirely local to your premises.

That’s only true for TT systems, which I wouldn’t expect to feature in a – presumably urban – hospital building. The more common arrangement (in the UK, at least) used¹ to be to have a separate Earth conductor (usually the cable shield) back to the earth point at the substation (TN-S). These days, the approach used is to connect the Earth to the Neutral conductor at the service head (TN-C-S) and to ensure that Neutral, which is the metal sheath of modern “coaxial” supply cables, is earthed at regular intervals on its way back to the substation – which gives TN-C-S its other name of Protective Multiple Earthing (or PME).

Whilst bonding water and gas pipes to Earth is done, it’s usually for the opposite reason: to ensure that if the Earth conductor within the property becomes live for some reason (perhaps a broken Neutral on a TN-C-S system between the service head and the first protective earth point), then all exposed metalwork in the building is held at the same potential. It’s this which makes installing car chargers on TN-C-S supplies so much fun, as you’re not allowed to connect the exposed metalwork outside the building to the TN-C-S Earth connection inside because it’s not possible to guarantee that everything within reach of the car is equipotentially bonded.

The potentially bigger concerns with running a cabled LAN to an external building are ensuring that you’re not inadvertently exporting an Earth connection from inside the property to somewhere that BS7671 says it shouldn’t be (see above), or providing an easy route for lighting strikes into the property.

¹ Many decades ago.

Something else to consider is that your earth connection isn’t supplied to you from the substation

There are many cases where it is. Sometimes bonded to the neutral, which means PME is required inside the premises. Lots of electrical equipment is now double insulated (two concentric squares) and does not require an earth. If you have equipment without the two concentric squares and it has no earth, then cut the plug off.

Quite often the property will have a earth stake which is also connected. It used to be the incoming water main (never the gas main) but that worked less well with plastic pipes.

The potentially bigger concerns with running a cabled LAN to an external building are ensuring that you’re not inadvertently exporting an Earth connection from inside the property to somewhere that BS7671 says it shouldn’t be (see above), or providing an easy route for lighting strikes into the property.

You can spend time and check what is supposed to be there and have it checked to prove it’s there. I just work on the safer basis that doing the interconnect with fibre eliminates the question.

Sometimes bonded to the neutral, which means PME is required inside the premises.

Outside, surely? The “multiple” in PME refers to the multiple places that the Neutral is earthed between the property and the substation, so as to limit the number of locations where a Neutral break could make the property’s Earth live at line potential.

No. (Well it is true what you say, but also inside.) If the neutral is bonded to the earth then anything inside the premises that might find its own way to earth, metal sinks, etc. must be bonded to the neutral otherwise under fault conditions the neutral might go to a few kV but the actual earth won’t. Or vice versa. AIUI. It protects against you touching the metal sink and (e.g.) the casing of an electrical appliance.

If the neutral is bonded to the earth then anything inside the premises that might find its own way to earth, metal sinks, etc. must be bonded to the neutral otherwise under fault conditions the neutral might go to a few kV but the actual earth won’t.

No. In a PME/TN-C-S system, exposed metalwork, pipes, sinks and so on are bonded to Earth, not Neutral. The Earth, in turn, is derived from the Neutral in one location and one location only: the supplier cut-out, on the supply side of the meter and consumer unit.

Aside from anything else, doing otherwise will make the use of RCDs and RCCBs a little tricky.

Earth, neutral are bonded together at one point, on the supply side of the consumer unit. That’s what you bond to.

Also tricky if you get the neutrals mixed up.

For everyone interested,
I finally found the time to upload the source for my Wake up on LAN on the RISC OS Community space on github.com, link here:

https://github.com/RISC-OS-Community/WakeOnLAN

It’s the initial commit, but GCC on RISC OS 5 seems to be able to compile it fine. Instructions provided on the read me.

This tool works either via command line or via Desktop. Any test would be very much appreciated, thanks!