There is a similar self-test on the refrigerated snack vending machines, of the variety that have a stacked array of internal turntables and small clear plastic doors on the front, allowing access to the contents (usually, stuff like pre-packaged and ultra-preservative-laden doughnuts, cheeseburgers(?!), and an unimpressive selection of not so fresh fruit...

The two buttons on the front that rotate the turntables left or right, if both pressed simultaneously, will cause the machine's vacuum flourescent display to show the date, time, and temperature.

I'm pretty sure almost all refrigerated machines have a feature like this, allowing the service person to easily check the internal temperature before reloading it.