What does "Device missing from piston" mean?


I have a piston that uses a virtual contact sensor. When I save the piston, I get the following message in the log:

Device missing from piston. Loading all from parent (40ms)

I’ve confirmed the device exists and is available to Webcore. I can also see and control it from a HE dashboard. The piston failed to execute properly last night and I’m wondering if the error in the log is indicative of the problem.


Are there any other devices in the piston that are not present (or been removed)? These will show as a long placeholder name.


No, the piston just uses the one device and I’ve confirmed the device exists and is accessible. After I posted my question, I edited and saved another piston that uses a virtual device and I see the same message. So it seems to have something to do with the fact the piston uses a virtual device.


After you edit a piston and save it, the piston refreshes device and subscriptions during the dummy walk thru.

So this is the reload of the cache.

You see this because you have debug logs enabled on the piston, it is just more debug information.