Trigger a device ( if lamp is offline)

I am wondering if we can create a scene using the condition : if lamp is OFFLINE then turn on Generator.
I mean to trigger a device in case another device is offline and not OFF. Please how can I do this. Because I need to turn on the generator when the power goes off On a device. (The generator already has a power backup)


Not support this feature because the devices OFFLINE happens, no matter the router’s issue or ISP failure or something else, lots of cases may cause the wrong action chain.

This is a “in the meantime” suggestion until someone comes up with a “offline” trigger.
How about putting a camera on something in there.
How about putting a ribbon hanging down being blown by a fan. You can pull up the camera, see if something is okay or not, and remotely turn the generator on

Yes it is a bit silly that this event (device is offline) is able to generate a notification in the eWeLinkApp but does not appear as an input for a scene.

“If device is offline for 5 minutes… trigger scene”

We need more event triggers for the scenes.


a case of mine
there’s a light switch that I set ‘power-on-state’ to ON
then I would like this light switch to trigger when it is ON, turn on few more other lights. It works if I use app to turn it on/off (physically switch is ON).
Now if I turn it off physically while it is ON, then I turn it on right afterward, the routine can’t be triggered. I guess it is not recognizing state from OFFLINE to ON, it can only recognize state from OFF to ON

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I am coming late to this discussion because I presently have the exact same situation as elie_t originally. Has anyone figured a way to start a generator when a device is offline (ie house power failure) ? My understanding is that if a device is offline because of a power failure both my router and remote start relay (sonoff basic) are offline as well thereby unable to communicate and/or operate a scene. Or did I miss something? Thks

Hi there, yes you’re right that if a device is offline becasue of the blackout, then all other smart devices as well as the wifi router are offline. The scenes won’t work in this case as our server is not able to communicate or send commands to all these devices.

This is not actually true for my case. In my case, the Stove and Geyser will be offline and the other devices running from the Battery will be on-line.
It could trigger a state where AC mains power is failed.
In this state I want most high power devices to be switched off.
In South Africa, this will be a very useful feature and we are enduring 3-4 “load shedding” events each day.


The device using the battery is running ≠ online, because at this time the router has already disconnected from the network due to the power outage, am I understanding correctly?

or you have series zigbee device and NS-Pro,and keep them power on with dynamo,to ensure devices can execute the scene without network

You can do this with a door sensor modification. Buy a small 220 volt (or more precisely what your mains voltage is) relay and plug it into the network that goes offline. You need to open the door sensor and bring out two wires that you will connect to the 220V sockets. relay. If you cannot do this manipulation, look for an electrician. In this case, you will simulate the opening and closing of the door when the power is turned off and on. Once you have this option you will be able to make your scenes as well. It has been tested and works for 3 years now!


can u please list the door sensor and the relay
plz if possible a diy video

Any udpate if this feature is going to be available soon (triggering a scene when device is offline)


If you need a solution for today…

Macrodroid + ewelink app

Macrodroid observes a specific part of the active ewelink application and waits for the offline key word to appear and performs actions as desired.

Web browser + PageProbe

PP observes the live ewelink web page and waits for the “Offline” key word in a specific place, device tile and responds via a webhook call…

Thanks alot! I will try this as a workaround

I’m sorry, but the relays are not at my place, but 50, 60 kilometers from me. When I go for preventive maintenance I will make a video and send it.

You can use the Sonoff 4CH PRO device to check the device’s power status. lack of power will switch the relay and turn on the emergency power supply.

Doesn’t your generator starts automatically when the power is off?
Usually most of generators have an auto start function.