The control cabinet is the core of the brewery's electrical system. The main component is the Programmable Logic Controller (PLC). This device, the brain of the brewery, communicates with Command Central and sends output signals to the pumps, valves, signal lights and burner. The PLC also converts signals from the thermocouples and flowmeters into data that can be displayed on the screen. Pump and mixer motors are all controlled by variable frequency drives connected to the PLC via MODBUS.