Invalid Device Variable - Smartthings multi function sensor



I’m new to webcore, I’m trying to get this to work:

I’m trying to display how long the contact has been open, if it’s been left open for 10 seconds (as a test)

When editing the piston, it says:

“Invalid device variable Mag Lock Engaged”

Can someone give me a pointer on what this means, how I find out what the correct device variable should be?


Post the green snapshot


I won’t be as good help as @eibyer
I just wanted to mention something:
With webcore and/or St apps, pistons or automations that happens in seconds are not really reliable.

  • If open for 4 seconds
  • if changes in 3 seconds

I’d use 20-30 seconds for any testing and/or piston.
Webcore is the best out there but not that fast yet (cloud etc)


Here is the image of the piston which is posted on the ST forum :slight_smile:



Functions are case sensitive so check that age() function, also what is the actual name of the device? Is it Mag Lock Engaged ?


thanks, all sorted now, didn’t realise Mag Lock Engaged was a device in the original piston, doh