Do regular grocery stores use a similar system? Or are locally controlled, simpler systems?

I've noticed stores going to central coolant lines going to cold cases more and more lately. Its all still industrial control. Ideally.

You can stick with local control and no internet access, all of the major BAS integrators offer completely offline systems. A BAS system is pretty simple, there are microcontrollers with binary and analog inputs and outputs that get networked together (RS-485, Ethernet, ARCnet), sensors and relays get wired to the microcontrollers. The microcontroller network is usually connected to a control panel that orchestrates the controllers, this is what you can connect to via the internet or a local pc not attached to the internet.

But pretty much any grocery store with multiple refrigerated/freezer cases is going to have an automation system that runs it.