A proper shutdown of the system needs to be done in two steps.
The first step is to turn the power off on the gateway. The gateway has a power button for turning the gateway off and on. Press and hold the power button for about 1 second to start the shutdown process. The gateway will go into it's power down cycle and after a short time the power button will change from green to red. Once the gateway has shut down, you can shut the power off on the entire system by switching the circuit breakers in the bottom left corner of the cabinet.
Remember that when you are shutting down the system the complete control process is offline.