Thermostat Variables - is there a variable to detect when furnaces comes on?

[TesterGuy2008]

I was curious to know if I could count, how many times, my furnace turned on during a day, and perhaps how long it was on before it reached temperature?

Perhaps I have to write a program to monitor setpoint - and then a timer to see how long it takes to get to temperature?

I see all these Device variables - but cannot find any documentation on what these variables mean?   Does anyone have any documentation for these?

Thanks