Home Automation & Solar Integration & Installation Company

The central control design method uses remote or hardwire control switches to control all your lighting needs in the house.
Data communication wiring from keypad is routed back to microprocessor to allow both type of user interfaces to communicate control commands.
Automated lighting control can also be integrated into the home system to control lighting on and off automatically. When an individual enters a specific room in the home, the lighting serving the room will immediately be turned on and the light to continue to be on as long as you are in the room.

Light Types
There are four basic types of lighting: incandescent, fluorescent, high-intensity discharge, and low-pressure sodium. Incandescent lighting is the most common type of lighting used in homes. Fluorescent lighting is used primarily in commercial indoor lighting systems, while high-intensity discharge lighting is used only for outdoor lighting applications. Low-pressure sodium lighting is used where color rendering is not important, such as highway and security lighting. These lighting types vary widely in their construction, efficiency, color characteristics, and lamp life.

Lighting System Concepts
A lighting subsystem's primary function is to create custom lighting scenes that enhance the beauty of the home. By pushing one button on a keypad, specific lights can be dimmed or a romantic dinner or another button can be programmed to turn on and dim specific lighting to create a party atmosphere.

A scene is a predetermined light level for a zone or group of lights. The light level may be the same for all lights in a scene, or each light may be set to an individual level from off to full on. The lights in a scene may be all the lights in a room, or all the controlled lights in the house depending on how the scene is set up.

A scene typically represents a combination of light levels associated with an activity. For example, a scene called "dinner" may be defined for all the lights in the living room and dining room such that the dining room lights are at 100% brightness and the living room ceiling lights are at 20% and the living room lamps are at 40%.
Scenes may also be associated with the state of another subsystem in the house such as the security system. Outputs from any device (thermostat, security alarm, driveway sensor, etc.) can be used to trigger a lighting scene. The following table gives examples of three scenes associated with states of the security system.

Switch closure - the homeowner presses a button on a keypad or switch

Time - scenes can be programmed to execute at a time of day

Sunrise/sunset - controllers can use an outside light level sensor or, if they have enough programming capability, can keep a table of local sunrise/sunset times for any date.

Contact closure - any contact closure such as a magnetic door sensor or other security sensor can be used to execute a scene. A magnetic sensor placed on a closet door, for example, can be used to control the light in a closet.

Lighting Controls
Typical central control lighting system design. The controller handles on/off/dim functions of all
attached branch lighting circuits based on user input from keypads, switches, and remote controls.

Distributed Control System
Distributed lighting control systems invariably use PLC (Power Line Carrier) technology such as X10 to control light loads. There are a wide range of PLC controllers and modules available to handle almost any lighting (and appliance) load in the home. For more details on PLC signaling technology and X10 modules, see Section 2. As discussed in Section 2, modules and controllers make up most of the system components

Lighting Controls
Typical distributed control lighting system design. The system uses PLC technology to perform on/off/dim
functions in X10 light switches and outlets. Control can be from anywhere in the electrical system wiring.

Switchable outlets can replace traditional wall outlets to control plug-in lights. Dimmable and switchable only plug-in modules can be used in existing wall outlets to control lamps or other existing light fixtures with a cord.

Several different types of controllers are available. Programmable controllers can be used to configure scenes based on events such as the time of day. Keypad-like wall switches can control several individual X10 devices.

Zones consisting of several fixtures can be established by combining switching modules into a group by assigning them the same house and unit code. Modules with the same house/unit code will operate identically.

Scenes can be programmed into several wall mount touchscreens or using a PC interfaced to the power line and running lighting automation software. Several wall switches are capable of "learning" scene setting and recalling the scene upon receiving a specific X10 code.

IR and RF remote control devices are also available to control individual modules or groups of modules assigned the same code.

Since PLC distributed control lighting system components rely on the power line as a network, they are subject to potential problems with power line communications and some skill (and network conditioning hardware) may be required to achieve a reliable system, but they have several advantages over central control systems:

They are retrofitable. Most X10 lighting modules are either plugged into an existing outlet, or replace traditional light switches. Other components can be connected to existing electrical wiring.

They use traditional electrical wiring. They do not require any special house wiring techniques or additional control signal wiring. Extra electrical wiring may be needed in a location where a controller is mounted, typically at eye level on a wall surface.
Interface with Home Automation Systems
Both types of lighting systems can be interfaced to a whole house automation system or to a PC for more elaborate control. Central control systems typically have an EIA-232 (often referred to by its older designation of RS-232) serial computer interface. The software used to perform the interface is proprietary to each manufacture. The distributed control PLC system can be easily controlled by any device with an X10 PLC interface. There are several PC to X10 power line interface devices available with PC software included.

Interface with Home Automation Systems
Both types of lighting systems can be interfaced to a whole house automation system or to a PC for more elaborate control. Central control systems typically have an EIA-232 (often referred to by its older designation of RS-232) serial computer interface. The software used to perform the interface is proprietary to each manufacture. The distributed control PLC system can be easily controlled by any device with an X10 PLC interface. There are several PC to X10 power line interface devices available with PC software included.

Lighting Controls
Components of a central control system all connect to the central control panel through electrical wiring or dedicated control wiring.

Central Control Panel
The central controller is usually contained in a large panel mounted near the main electrical load center of the home and contains a microcontroller for all system operation. The microcontroller is programmed during installation to assign keypad switches to lights and/or lighting scenes, create lighting zones and scenes, and assign contact closure inputs to lights or scenes. It also contains the remote controlled lighting zone switches, both on/off only and dimmable to handle the hardwired lighting circuits. It is wired similarly to an electrical panel since electrical wiring from lighting circuits is brought to the lighting panel and connected to an internal switch circuit.

Other Systems
There are lighting control systems that combine some of the features of both distributed and central control.

The ALC light switch line from OnQ Technologies replaces standard light switches but can be controlled from a home automation system using a 2-conductor wiring bus. The 2-wire twisted-pair cable must be prewired from the home automation system location to each switch location using either a home-run or daisy-chain wiring configuration.

Lighting Controls
Typical wiring for ALC switches. The switches are interfaced to a home automation system by installation of
an interface card. Programming of the switch operation is from the home automation system user interface.

ALC wall switches include four types: Relay Switches (for on-off lighting/power control), Dimmer Switches (for light dimming control), Auxiliary Switches (for "slave" of a relay or dimmer switch) and Program Switches for programmed control of a relay or dimmer switch.