Using the 4503DX master, and the master can be infinitely expanded.
Apply that few homes or museums, restaurants, shopping center and so on.
The master you can do the work of their respective sets, but can also be controlled by the master set.
The 4503DX internal RTC clock you can set the time switch functions such as lights or electric curtains.
The 4503DX can configure Group Effect that synchronous Master to Master effects.