Can you use automation to test if the power is on or not?

[hexges]

I want to be able to test if the power is off to open a specific door otherwise keep that door from being used. Or  for a check point?

[PhailRaptor]

Haven't toyed with logic circuits yet, but based on posts I've been seeing around, I don't think there's a way to check if a circuit currently has power.  The closest you can come is using a small Battery and a very carefully calibrated Thermal Sensor.  When the Battery runs out of power, it will stop producing Heat, which can be used to trip the Thermal Sensor.

 

You could then use that Thermal Sensor to open the specific Door.  Don't use the Checkpoint, though, because Dupes will get "stuck" there until the Checkpoint opens, when they're assigned a task beyond it.

[GreatGameDota]

There's quite a few ways to do it. I've seen temperature sensors, gas pressure sensors, and the easiest, the manual gen sensor.

[Rocoto]

Have a look at this. In the thread are also some other circuits you could use.