My house display for 2017 Christmas. The outside lights and living room window lights are controlled by an Allen Bradley SLC5/04 PLC. The door wreath is controlled by a Siemens S2-200 PLC, with the power to it controlled by the living room SLC5/04. Most of the light strings have been cut into 10 bulb sections to run on 24 volts DC provided by separate power supplies. The flickering candles in the kitchen window are 4 volt bulbs wired to a TTL transistor logic card, and each of the 7 is controlled with it's own subroutine. TO get 4 volts I have a 5 volt power supply run through a potentiometer to reduce the voltage to 3.7 volts - it is easier on the bulbs and makes them a little dimmer than full brightness so they appear more like candles.
The kitchen window is controlled by a SLC5/03 PLC, and another SLC5/03 controls the tree that I put out in the side yard this year.
The PLC's are synced with messaging by a home control SLC5/05 in my home office, through NET-ENI's. A network COM port on the tree PLC is messaged to through a data-subscriber on the HMI.
All features (along with the home controls, monitoring and alarms) are controllable and adjustable by a computer and a Windows tablet both running AdvancedHMI.