On/Off protection for relay switch

[maor 0]

Hi, 

Is there a way to lock the relay operation for changes coming directly from the app/gui, and allow them only through scenes?

The rational is not allowing any state change before doing some checks. I have two dosing pumps feed my pool with chlorine & acid and I don't want to allow one of them to start if the other one is working. A mistakenly 'on' pressing directly on the device itself, in the app or gui, can be harmful.

If a complete lock isn't possible, maybe there's a pin protected operation option?

 

Any idea?

 

Thanks!

 

[Martin_N 148]

For critical applications, there is actually only the right solution, and that is the mutual blocking with the help of additional relays. The principle is that by starting one relay, the power supply of the circuit of the other relay is automatically interrupted (NC contact).
If it's still current, I can paint the wiring diagram. Kdyztak napis.
eM.

[Tim__ 116]

In HC2 at least, you can hide devices in the the GUI so they aren't used by accident. There's a check box in the devices advanced tab called "hide devices in system" or similar.

 

I have a similar mutual blocking use case that I'm currently implementing, using a Smart Implant and a RGBW device (this gives four outputs, so I have 6 outputs in total), external relays and a virtual device to tie it all together. I have already configured the relays as @Martin_N has suggested.

 

Because I'm using a virtual scene, I can write the state checks into the code when a button is pressed, and abort the scene if the current state dictates it. I think I will need to use a global variable or two to record the state.

 

I'm currently playing with some watchdog code, that checks for illegal state combinations and resets relays to a safe state, just in case! I'm putting this code in the "main loop" section of the virtual device, which is automatically executed every second.

 

There is a good virtual device tutorial (for HC2 anyway) if you search in the tutorials section of this forum. I realise your initial post was a few months ago, @maor how did you go with your project?