LCN is a bus based building automation system. Control modules are installed into wall switch or distribution boxes to tap AC lines. Once connected each module can begin transmitting and receiving commands in a network automatically formed with other modules.
Initially a 4-wire (or more) AC cable should be installed. One of these extra wires is then used solely for data transfer between modules. Bus modules are units that are responsible for the data transfer from one unit to another. Each Bus module is connected directly to phase (L1, L2; L3/X,Y, Z), neutral and the extra data wire. Bus Modules feature:

• Microprocessor controlled
• Built-in power supply
• sensor and actor combined in one unit
• 2 independent power outputs ranging from 250VA to 2000VA
• Outputs can be operated as switch or dimmer
• Up to 3 extension ports: T-port for sensors (light, temp., etc.), I-port for pulses (IR Remote Control, wind speedometer, keyless entry system, etc.) and P-port for relay blocks (digital output) and binary input

Firmware functions include: Counting, Timer, Logic control, Digital I/O, Analogue I/O, Remote Control. The same applies to any step-by-step extensions which may become necessary in the future.