The FN485 modules are daisy-chained on a two-wire bus. The bus length can be up to 1200m. Using multiple buses is also possible.
3 Channel FN485 Bus Line Voltage Dimmer
The FN485-3x1kDH three channel Intelligent DIN Rail Mountable Dimmer is used for switching and dimming incandescent and halogen lighting loads either via its local inputs or via FN485 bus.