Running my weather station at a 120km distance from where I am often residing becomes problematic . As well as the Vantage pro with a serial to USB computer hook-up, 3 cameras display views on my web page, 2 of them internet and one an old video camera with a high power zoom to display surf conditions connected through a USB Ezycap device.  One of these seems to regularly "hang" even though it is hard wired to ethernet which requires powering off  and then on again. The potential for hiccups is pretty high and of course Murphy always ensures it works fine when one is on the premises!  I have tried running the whole system on one laptop, but it proved unstable especially because of the USB to Com devices, so presently a laptop runs all the cameras and Weather Display is on the Micro Windows 10 box which is reviewed in an earlier post.
In most cases, powering off and then back on solves most of the "hang" problems. Doing that over a distance of 120kms presents a teeny weeny problem. Lately I've come across just the bees knees to solve it.
I  discovered on Ebay a couple of gadgets by the name of Sonoff. You can purchase either a small circuit board or a complete 230v 10A switch. The circuit board cost me NZ$12 free postage and the switch NZ$14 again free post. A picture of the complete switch and board is attached along with my phone screen with the app running.
Both connect to your wireless router and you communicate with it through a phone App called eWeLink.
Firstly I had to get into the Bios of the computer and ensure that it was set to boot on Power. I think most computers will have a setting for this. Then it is just a matter of plugging the 12v supply which powers the micro computer into the Sonoff switch which I had prevously linked to my router and turn it on (and off) with my phone. Next time it goes "off-line" I can at least give it the power off, power on treatment to re-boot it and hopefully clear the problem.

I have an I7 desktop which I don't like to leave running while I am away. Automated remote control is installed on all the computers and it is useful to be able power it on to monitor what is going on with the network and make tweaks to my webserver when needed. This is where the little circuit board comes in handy. It does require a little skill as you need to open the case of your computer, locate the wiring to the On/Off switch and connect 2 pieces of wire so that when they are bridged together it turns the computer on. These wires are connected to the relay on the Sonoff board.
The board has what is called an "inching" function which allows you to set a time the relay will be activated for after the ON button is pressed in the App. In this case I set it for 1 second which is the amount of time the press button on the computer takes to start it. As you can see, I mounted the board in a small plastic box and the wires to the right go to the computer switch. It is powered by a standard USB 5v cable. The charger was bought from PBtech for about $9.
Here in NZ, smart control switches are starting to make an appearance, but at a considerable cost. With these you can experiment without it costing an arm and a leg!
Cheers,

Tony C.