Patent Publication Number: US-8531135-B2

Title: Lighting system and method for controlling the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority under 35 U.S.C. §119 to Korean Application Nos. 10-2011-0026985 and 10-2011-0026986 filed in Korea on Mar. 25, 2011, whose entire disclosures are hereby incorporated by reference. 
     BACKGROUND 
     1. Field 
     A lighting system and method for controlling the same are disclosed herein. The lighting system and method of the present disclosure allows a more efficient utilization and conservation of energy resources. 
     2. Background 
     Lighting systems and methods for controlling the same are known. However, they suffer from various disadvantages. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
         FIG. 1  is a schematic diagram of a lighting system according to an embodiment of the present disclosure; 
         FIG. 2  is a block diagram of the lighting system of  FIG. 1 ; 
         FIG. 3  is a block diagram of a central lighting controller according to an embodiment of the present disclosure; 
         FIG. 4  is a diagram illustrating a connection between a bridge device and a plurality lighting apparatuses according to an embodiment of the present disclosure; 
         FIG. 5  is a schematic diagram of a connection module of a bridge device according to an embodiment of the present disclosure; 
         FIG. 6  is a logical block diagram of a connection module of a lighting apparatus according to an embodiment of the present disclosure; 
         FIG. 7  is a schematic diagram of a connection module of a lighting apparatus according to an embodiment of the present disclosure; 
         FIG. 8  is a flow chart of a method for controlling a connection module according to an embodiment of the present disclosure; 
         FIG. 9  illustrates a format of a data packet according to an embodiment of the present disclosure; 
         FIG. 10  shows information related to command codes contained in a packet frame according to an embodiment of the present disclosure; 
         FIG. 11  is a flowchart illustrating a process for address assignment according to one embodiment of the present disclosure; 
         FIG. 12  is a flowchart illustrating a process for address assignment according to one embodiment of the present disclosure; 
         FIG. 13  is a flowchart illustrating a process for address assignment according to one embodiment of the present disclosure; and 
         FIG. 14  is a flowchart illustrating a method for controlling a lighting system according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In general, incandescent lamps, discharge lamps, and fluorescent lamps are used most commonly as light sources for various purposes, such as domestic, landscape, industrial, or other appropriate types of lighting applications. These types of light sources suffer from various disadvantages such as poor efficiency and large amounts of heat generation (e.g., incandescent lamps), high price and high operational voltage (e.g., discharge lamps), and may be harmful to the environment due to their use of mercury (e.g., fluorescent lamps). 
     Light emitting diode (LED) based light sources may overcome the drawbacks of these light sources. LEDs have advantages in efficiency, flexibility to emit light in a variety of colors, autonomy of design, and so on. The LED is a semiconductor device which emits light when a forward voltage is applied thereto. LEDs have a greater lifespan, lower power consumption, and electric, optical, and physical characteristics which are suitable for mass production when compared to incandescent, discharge, or fluorescent types of light sources. 
     Moreover, in a large building, a lighting system may include a large number of light sources. The lighting system as broadly disclosed and embodied herein may automatically assign a unique address to the plurality of lighting apparatuses and control the lighting apparatuses using the unique addresses to enable a more efficient management and operation of the lighting system. The lighting system may automatically detect and configure replaced or newly added lighting apparatuses to assign a new address. The lighting system and method for controlling and managing the same as disclosed herein allows a more efficient utilization and conservation of energy resources. 
       FIG. 1  is a schematic view of a lighting system and  FIG. 2  is a block diagram of the lighting system in accordance with an embodiment of the present disclosure. The lighting system  1  may include a terminal  10 , an interface  11 , a lighting controller  20 , a gateway  30 , bridge devices  40 ,  50 , a plurality of lighting apparatuses  41  to N,  51  to M (N, M=a positive integer) connected to the bridge devices  40 ,  50  to enable communication, a program switch  60 , and a sensor  70 . It should be appreciated that the lighting system  1  may include various combinations of the elements which are shown in  FIG. 1 . 
     The terminal  10  may be connected to the lighting controller  20  to control the lighting part L. The lighting part L may include one or more of the bridge devices  40 ,  50 , the lighting apparatuses  41  to N,  51  to M, the program switch  60 , or the sensor  70 . The terminal  10  may be connected to the lighting controller  20  to communicate over one or more of a Transfer Control Protocol/Internet Protocol (TCP/IP), a Simple Object Access Protocol/Extensible Mark-up Language (SOAP/XML), a Building Automation and Control Network (BACnet), or another appropriate type of protocol to exchange information within the lighting system  1 . 
     The terminal  10  may store setup information for the lighting part L. The terminal  10  may manage state information and power consumption in real-time, including turning the lighting apparatuses  41  to N,  51  to M on/off or changing the light intensity of the lighting apparatuses  41  to N,  51  to M mounted in a particular zone. The terminal  10  may also detect areas which may be using unnecessary energy to minimize waste, manage equipment in the building, manage maintenance of equipment operation, manage maintenance of an inside environment of the building, manage energy and materials consumed through the above management operations, or the like. The terminal  10  may also initiate configuration of the lighting apparatuses  41  to N,  51  to M, for example, to initialize the addresses of one or more of the lighting apparatuses  41  to N,  51  to M. 
     The terminal  10  may be a desktop computer, a laptop, a display panel, a Personal Digital Assistance (PDA), a tablet, or another appropriate type of device capable of performing the management functions. The terminal  10  may be connected over a distributed network through an appropriate type of network protocol (e.g., TCP/IP). The terminal  10  may be connected via wired or wireless connections. Moreover, the terminal  10  may be a Web server connected over the Internet to remotely control and manage the lighting part L. 
     In certain embodiments, a plurality of terminals  10  may be provided such that each terminal  10  may perform the management functions to control the lighting system  1 . In this case, the plurality of terminals  10  may communicate with each other to synchronize information related to the management of the lighting system  1  such as operating schedules, or the like. 
     The interface  11  may be a display panel for inputting control inputs or displaying state information of the lighting system  1 . The interface  11  may have a form factor which is smaller in size when compared to the terminal  10  which may allow the interface  11  to be easily installed throughout the building B. For example, the interface  11  may have a size and shape suitable to be wall mounted or used as a mobile device. The interface  11  may be provided on each floor or zone in the building B to receive control inputs from a user and to display a Graphical User Interface (GUI) for controlling and monitoring the lighting apparatuses  41  to N,  51  to M in the lighting system  1 . 
     The display of the interface  11  may be a touch screen display. The interface  11  may communicate with the lighting controller  20 , for example, to transmit inputs received through the GUI to the lighting controller  20  for controlling various groups/zones of lighting apparatuses. For example, the interface  11  may transmit control information to the lighting controller  20  to control an individual lighting apparatus or a group of lighting apparatuses such as an entire floor or building. The interface  11  may also receive status information, or the like, from the lighting controller  20 . The interface  11  may display the received information on the GUI. 
     It should be appreciated that, while the interface  11  is described hereinabove as a display panel, the present disclosure is not limited thereto. For example, the interface  11  may be configured to have the same functionality as the terminal  10 . The interface  11  may be a desktop terminal (e.g., a desktop computer), laptop, PDA, tablet, or another appropriate type of computing device. Moreover, while the terminal  10  and the interface  11  have been disclosed as being connected through the lighting controller  20 , it should be appreciated that the terminal  10  and interface  11  may be connected such that signals are not necessarily routed through the lighting controller  20 . For example, the terminal  10  and the interface  11  may be directly connected to each other or connected in a distributed network configuration with the lighting controller  20 . Moreover, the interface  11  may be configured to communicate over various types of communication protocols, similar to the terminal  10  as previously described. 
     Moreover, one or more of the terminals  10  or the interfaces  11  may be configured as a management terminal while the remaining terminals  10  or interfaces  11  may be configured as user interfaces for state monitoring and for inputting user commands. A management terminal may be configured to have additional functionality than the remaining terminals, such as the capability to initiate assignment of addresses for the lighting apparatuses, configure zones or control groups to control a group of lighting, centrally store scheduling or user preference information, or the like. 
     The lighting controller  20  may be provided to control the operation of the lighting apparatuses  41  to N,  51  to M based on received inputs or an operational state of the lighting part L. The lighting controller  20  may be connected to the terminal  10 , the interface  11 , and the gateway  30 . The lighting controller  20  may receive various control inputs for controlling the lighting apparatuses  41  to N,  51  to M from the terminal  10  or interface  11  and transmit appropriate control signals to the gateway  30  to control the lighting part L. The lighting controller  20  may receive monitoring information from the sensor  70 . The lighting controller  20  may directly control the lighting apparatuses  41  to N,  51  to M based on the received monitoring information and/or forward the monitoring information to the terminal  10  and interface  11  for processing and display thereon. 
     The lighting controller  20  may communicate with the monitoring terminal  10  or the interface  11  using various types of protocols, for example, SOAP or BACnet protocols in which XML based messages are exchanged over a network using HyperText Transfer Protocol (HTTP), Hypertext Transfer Protocol over Secure Socket Layer (HTTPS), Simple Mail Transfer Protocol (SMTP), or another appropriate type of protocol. 
     Moreover, the lighting controller  20  may store the addresses for each lighting apparatus  41  to N,  51  to M as well as the switch  60  and sensor  70 . The lighting controller  20  may also store user preference information, scheduling information, zone or control group information, or another appropriate type of information to control and manage the lighting system  1 . The lighting controller  20  may also control address configuration for the plurality of lighting apparatuses  41  to N,  51  to M through the gateway  30  and the bridge devices  40 ,  50 . For example, the lighting controller  20  may generate data packets including address information for setting the address in each of the lighting apparatuses. In certain embodiments, the bridge devices  40 ,  50  may be configured to control address configuration for the lighting apparatuses  41  to N,  51  to M, as described in further detail hereinafter. Moreover, the lighting controller  20  or the bridge devices  40 ,  50  may include an address assigning device for controlling the address assigning process including generating the addresses for the lighting apparatuses  41  to N,  51  to M. 
     The lighting controller  20  may be installed separately or may be integrated into a terminal  10 . For example, the terminal  10  may be configured as a central management terminal and installed in a main equipment room or at a remote location outside the building B and the lighting controller  20  may be mounted on each floor of the building B. Alternatively, the terminal  10  and the lighting controller  20  may be integrated and installed as a single apparatus. 
     The gateway  30  may communicate with the lighting controller  20  to receive control signals from the lighting controller  20  for group/individual lighting control. The gateway  30  may forward the received control signals to the lighting part L (e.g., bridge device, lighting apparatus, switch, or sensor) to control the same. The gateway  30  may also relay messages from the lighting part L to the controller  20 . The gateway  30  may communicate with the lighting controller  20 , the bridge devices  40 ,  50 , the switch  60 , or sensor  70  over a wireless or wired connection. The gateway  30  may be configured to communicate with the controller  20  over TCP/IP or another appropriate type of communication protocol. In one embodiment, the gateway  30  may be a Zigbee gateway. 
     A plurality of bridge devices  40 ,  50  may be connected to the gateway  30  and the plurality of the lighting apparatuses  41  to N,  51  to M to enable communication therewith for transmitting the control signals from the gateway  30  to the lighting apparatuses  41  to N and  51  to M. The bridge devices  40 ,  50  may also transmit a response or event information from the lighting apparatuses  41  to N,  51  to M to the gateway  30 . Moreover, the bridge devices  40 ,  50  may be configured to control the address configuration for the lighting apparatuses  41  to N,  51  to M. 
     The plurality of bridges  40 ,  50  may each be connected to a group of lighting apparatus. For example, the first bridge device  40  may be connected to a first group of lighting apparatuses  41  to N and the second bridge device  50  may be connected to a second group of lighting apparatuses  51  to M to enable communication therewith. The bridge devices  40 ,  50  may be connected up to a prescribed maximum number of lighting apparatuses. In one embodiment, the bridge devices  40 ,  50  may be connected up to 12 lighting apparatuses. 
     The bridge devices  40 ,  50  may be connected to the gateway  30  using the Zigbee specification. The bridge devices  40 ,  50  may be connected to the lighting apparatuses  41  to N,  51  to M using the RS-485 protocol which is a serial communication protocol. An input received, for example, at the interface  11  may be transmitted to the lighting controller  20 , the gateway  30 , and the corresponding bridge device  40 ,  50  in succession. The bridge device  40  may transmit the received commands to the appropriate lighting apparatus through the serially connected lighting apparatuses  41  to N. Likewise, the bridge device  50  may forward the commands to an appropriate lighting apparatus  51  to M serially connected thereto. For example, a command to turn off lighting apparatus  42  may be serially transmitted through lighting apparatus  41 . 
     A response from the lighting apparatuses  41  to N,  51  to M may be transmitted to a corresponding bridge device  40 ,  50 , the gateway  30 , the lighting controller  20 , and the terminal  10  and the interface  11 , in succession. For example, data packets from the lighting apparatus  42  may be transmitted to lighting apparatus  41  and then to bridge device  40  over the RS-485 protocol. The data packets may then be forwarded to gateway  30  using Zigbee specification. 
     In accordance with the present disclosure, the bridge device  40 ,  50  may generate address data and transmit data packets including the address data to each serially connected lighting apparatuses  41  to N,  51  to M for configuring the addresses. The bridge device  40 ,  50  may convert received data packets into a format compatible with the destination lighting apparatus  41  to N,  51  to M. The bridge device  40 ,  50  may also format data received from the lighting apparatus  41  to N,  51  to M in a format compatible with the lighting controller  20 . Alternatively, the address data may be generated in the controller  20  rather than in the bridge device  40  and transmitted to a corresponding lighting apparatus  41  to N,  51  to M through the bridge device  40 . 
     The lighting apparatuses  41  to N,  51  to M may be one of a plurality of types of light sources including, for example, an LED type light source. The lighting apparatuses  41  to N,  51  to M provided in the building B may be a flat type or a bulb type light source. The lighting apparatuses  41  to N,  51  to M may include or more LEDs which have a color rendition which is higher than Ra 75, and an efficiency which is higher than 65 lm/W. 
     The lighting apparatuses  41  to N,  51  to M may be connected in series over the RS-485 protocol. Each lighting apparatus  41  to N,  51  to M may be configured to intercept or forward a control command received from a previous device. For example, a control command to initiate address configuration may be intercepted by a lighting apparatus to set a new address or transmitted in series to a subsequent lighting apparatus. The lighting apparatuses  41  to N,  51  to M may also include circuitry to control light intensity of the LEDs (e.g., dimming). 
     The building B may include a switch  60  to control one or more of the lighting apparatuses  41  to N,  51  to M (e.g., dimming or to turn the lighting apparatuses on/off), and a sensor  70  to sense light intensity, or the like. The switch  60  and sensor  70  may be integrated into the lighting apparatuses  41  to N,  51  to M or installed separately in the building B. 
     It should be appreciated that the connection scheme between the bridge devices  40 ,  50  and the gateway  30  may be the same as the connection scheme between the bridge devices  40 ,  50  and the lighting apparatuses  41  to N,  51  to M. For example, the bridge devices  40 ,  50  and the lighting apparatuses  41  to N,  51  to M may be configured to communicate according to the Zigbee standard. Simply for ease of description, however, the connection between the bridge devices  40 ,  50  and the lighting apparatuses  41  to N,  51  to M is described herein as being connected over the RS-485 protocol. 
     Moreover, it should be appreciated that the lighting system  1  may include a combination of the previously disclosed elements and is not limited to the configuration as illustrated in  FIGS. 1 and 2 . Furthermore, the lighting system  1  may be implemented as a hybrid solution as well as a legacy solution to interface with legacy lighting apparatuses. 
     For example, the hybrid solution may include a combination of devices, as shown in  FIGS. 1 and 2 . That is, the hybrid solution may include one or more bridge devices  40 ,  50 , gateways  30 , lighting apparatuses  41  to N,  51  to M, switches  60 , and/or sensors  70 . Alternatively, a legacy solution may include a lighting controller  20  connected according to a third-party protocol scheme to various combinations of a Network Control Unit (NCU), a Lighting Interface Unit (LIU), a Central Processing Unit (CPU), a Transmission Unit (TU), a relay, a program switch, etc. The address initialization of the lighting apparatuses as broadly disclosed and embodied herein may be applicable to legacy lighting apparatuses. 
       FIG. 3  is a block diagram of the central lighting controller  20  of  FIGS. 1 and 2 . The controller  20  may include a microprocessor  21 , a connection management module  22 , a communication module  23 , a SOAP connection manager  24 , and a BACnet connection manager  25 . 
     The microprocessor  21  may be configured for processing data for controlling the lighting part L. The microprocessor  21  may receive commands from the terminal  10  or interface  11  through the SOAP connection manager  24  and/or the BACnet connection manager  25 . The microprocessor  21  may process the received commands to generate a control data packet and transmit the generated control data packet to the lighting part L through the communication module  23 . Moreover, the microprocessor  21  may generate a response or event information related to the received commands and transmit the information to the terminal  10  or interface  11  through the connection management module  22 . 
     The microprocessor  21  may perform group based control, individual based control, pattern control, schedule based control, power failure and power recovery control, illumination sensor interoperable control, or the like, for controlling and monitoring the lighting apparatus  41  to N,  51  to M, the switch  60 , and/or the sensor  70 . 
     The communication module  23  may control communication between the lighting controller  20  and the gateway  30 . The communication module  23  may format or convert data received from the microprocessor  21  into a format compatible with the lighting apparatus  41  to N,  51  to M, the switch  60 , or the sensor  70 . The communication module  23  may transmit the formatted data to the gateway  30 . The communication module  23  and the gateway  30  may transmit and receive, for example, TCP/IP packets. In addition, the communication module  23  may transmit to the microprocessor  21  a response or event information received from the gateway  30 . 
     Upon receiving the control command from the terminal  10  or interface  11 , a corresponding one of the connection management module  22 , the SOAP connection manager  24 , or the BACnet connection manager  25  may convert the received control command into an internal language capable of being recognized by the lighting controller  20 . The formatted control command may then be transmitted to the microprocessor  21 . That is, one of the connection management module  22 , the SOAP connection manager  24 , or the BACnet connection manager  25  may interpret or convert the data from a protocol corresponding to either the terminal  10  or the interface  11  to the required format. 
       FIG. 4  is a diagram illustrating a connection between a bridge device and a plurality of lighting apparatuses according to an embodiment of the present disclosure. Simply for ease of description, reference is made hereinafter to the bridge device  40  and corresponding lighting apparatuses  41  to N of  FIG. 1 . It should be appreciated, however, that the present disclosure is not limited thereto and may be applicable to a various combination of multiple bridge devices and lighting apparatuses. 
     The bridge device  40  may be serially connected to lighting apparatus  41 , and lighting apparatus  41  may be serially connected to lighting apparatuses  42  and  43 , as shown. The bridge device  40  may be configured as a master device and the lighting apparatuses  41  to N may be configured as a slave device. The bridge device  40  may be connected to the lighting apparatuses  41  to N using the RS-485 communication protocol. However, as previously described, it should be appreciated that the scope or spirit of the present disclosure is not limited to the RS-485 communication protocol and may also be equally or similarly applied to other communication protocols as necessary. 
     The lighting apparatuses  41  to N may each include a corresponding light emitting module  421  to N′ and a connection module  451  to N″. Each light emitting module  421  to N′ may be connected to a corresponding connection module  451  to N″. The connection module  451  to N″ may provide power and control signals to the light emitting module  421  to N′ to control the operation of the LEDs. Moreover, the bridge device  40  and each of the lighting apparatuses  41  to N may be connected in series through the connection modules  451  to N″ of the respective lighting apparatuses  41  to N. The connection modules  451  to N″ may include a connection circuit to control a data connection to a subsequent connection module. The connection modules  451  to N″ may also be referred to herein as a control circuit or a connection controller. 
     The bridge device  40  may be connected to the connection module  451  of the first lighting apparatus  41 , and the connection module  451  may be connected to the next connection module  452  of the second lighting apparatus  42 , and so on. The bridge device  40  may be hardwired to the connection modules  451  to N″. The bridge device  40  may assign a unique address to the lighting apparatuses  41  to N through the wired data lines. The bridge device  40  may control the lighting apparatuses  41  to N using the unique addresses. 
     In association with the above-mentioned description, provided that the bridge device  40  is connected in series to the connection modules  451  to N″ of each lighting apparatus  41  to N according to the RS-485 communication protocol, an address assignment procedure for each lighting apparatus may be executed for group or individual control of the lighting apparatuses  41  to N. The address assigned to each lighting apparatus  41  to N may be unique within at least a specific region or area, e.g., floor or room. Here, it may be necessary that each lighting apparatus in the particular region have a unique address for individual control of each lighting apparatus. 
     The bridge device  40  and each connection module  451  to N″ may support the RS-485 communication protocol, and include a plurality of ports or connectors for connecting power and data according to the RS-485 communication protocol. For example, the bridge device  40  may include a port for power and data connection to the connection module  451  of the first lighting apparatus  41 . The connection modules for each subsequent lighting apparatuses connected in series may include an input and output ports for connection to the bridge device  40  through a connection module of a previous lighting apparatus. The input, output, and power ports may include at least one terminal and may include a variety of types of connectors. 
     For example, the bridge device  40  may include a port having terminals for two input lines and two output lines. The bridge device  40  may include a terminal P for receiving power from the first connection module  451  of the first lighting apparatus  41 . The bridge device  40  may also include data terminals A, B to exchange data with the first connection module  451 . The bridge device  40  may also include a ground terminal G. 
     The first connection module  451  of the first lighting apparatus  41  may include an input port, an output port, and a power port. The power port on the connection module  451  may be connected to the power terminal P of the bridge device  40  for supplying power thereto. The output power generated by the first lighting apparatus  41  may have, for example, a voltage level of +5V. The input port of the first lighting apparatus  41  may have three terminals for connection to the bridge device  40  including one ground and two data terminals. These terminals on the input port may be connected to the ground port G and data ports A and B on the bridge device  40 , respectively. The output port of the connection module  451  may also include three terminals, one ground and two data terminals. These output terminals may be connected to the corresponding terminals on the input port of a subsequent connection module (e.g., the connection module  452  of the second lighting apparatus  42 ). 
     As described above, the connection modules  451  to N″ may transmit data received from a previous device to a subsequent device without change. For example, each connection module  451  to N″ may relay received data to a connection module of a subsequent lighting apparatus according to the RS-485 communication protocol. Hence, data transmitted from the bridge device  40  may be serially transmitted to each of the plurality of lighting apparatuses  41  to N. Moreover, as described in further detail with reference to  FIG. 7  hereinafter, each connection module  451  to N″ may analyze a received data packet and control the data connection to a subsequent connection module based on the analysis. 
       FIG. 5  is a schematic diagram of a bridge device. The bridge device  40  may include an antenna  510 , a filter  520 , a transformer  530 , a controller  540 , a memory  550 , a driver  560 , a buffer  570 , a low drop-out regulator (LDO)  575 , an input/output (I/O) port  580 , and an interface (I/F) connector  585 . In addition, the bridge device  40  may communicate with an external lighting apparatus  590 . 
     The antenna  510  may transmit and receive radio frequency (RF) signals from the gateway  30 . The filter  520  may remove output harmonic components through a low pass filter (LPF). The filter  520  may also filter high frequency components through the LPF. 
     The transformer  530  may be implemented as a ‘balance to unbalance transformer’ (Balun) having a higher conversion rate when a high impedance balanced antenna is matched to a low impedance unbalanced receiver, transmitter, or transceiver. For example, a signal for the transformer  530  may be configured as a 100Ω differential signal. The 100Ω impedance may be converted to 50Ω impedance through an antenna according to transmission/reception (Tx/Rx) signals, and only the 2.4 GHz band signals may be filtered out. 
     The controller  540  may be a 2.4 GHz ZigBee wireless communication transceiver System on Chip (SoC) including an IEEE 802.15.4 MAC/PHY. The controller  540  may further include a processor, a flash memory (or SRAM), and an encryption module. Furthermore, the controller  540  may use an SPI (Ethernet, EEPROM), a TVVI (RTC module), or a Joint Test Action Group (JTAG) (SIF) interface. 
     The memory  550  may include an Electrically Erasable Programmable Read-Only Memory (EEPROM) acting as a non-volatile memory. For example, the memory  550  may have a storage capacity of 128 Kbytes, and may be used as a temporary data ROM (DataROM) when ZigBee firmware is wirelessly updated. 
     The driver  560  may enable long distance communication with an external device through a differential line according to a half duplex scheme for use in Universal Asynchronous Receiver/Transmitter (UART) communication. The buffer  570  may adjust brightness of an external device (e.g., a connection module) using a Pulse Width Modulation (PWM) scheme such as a 500 Hz pulse width modulation scheme. The LDO  575  may convert an input power supply voltage of 5V DC to a constant voltage of 3V DC to power components requiring 3V DC, such as a ZigBee chip. 
     The I/O port  580  may be connected to a plurality of lighting apparatuses through RS-485 communication based on the half-duplex scheme, such that it can independently control each of the plurality of lighting apparatuses. In one embodiment, the bridge device  40  may be connected up to 12 light emitting apparatuses. The I/O port  580  may receive an input voltage (e.g., 5V DC) through an external device to power internal circuits. 
     The I/F connector  585  may be connected to the 5V DC on the I/O port  580 , the LDO  575 , and the buffer  570 . The I/F connector  585  may receive the 5V DC power through the external device (e.g., the connected connection module  451 ), and may output a PWM signal of 5V, such that light dimming is achieved by PWM control. 
     If necessary, the bridge device  40  may be configured to include a function for testing a connection state between devices or a memory fusing function. In addition, the bridge device  40  may include a JTAG Connector to download and debug ZigBee software (S/W). 
       FIG. 6  is a logical block diagram of a connection module of a lighting apparatus according to an embodiment of the present disclosure. The connection module  451  of lighting apparatus  41 , taken as an example, may include a main module  610 , a packet parser &amp; handler  620 , a hardware abstraction layer (HAL)  630 , a UART manager  640 , a timer manager  650 , a serial manager  660 , and a configuration manager  670 . 
     The main module  610  may control the operation of the lighting apparatuses, and provide the infrastructure to implement a connection, communication, and control of the elements of the lighting apparatuses. The packet parser &amp; handler  620  may parse RS-485 packets including at least one of a control data or address data which is transmitted from the bridge device  40 , and may process data contained in the parsed RS-485 packets. 
     The HAL  630  is an aggregate (or set) of routines to process hardware-dependent items needed for implementing the I/O interface, interrupt control, and multi-processor communication, and may provide necessary interfaces and routines under control of the main module  610 . The UART manager  640  communicates with an external device through a differential line according to a half-duplex scheme for use in UART communication. 
     The timer manager  650  manages timing related to processing of control data and address data that are input through the bridge device  40 . The serial manager  660  transmits and receives RS-485 packets. The configuration manager  670  may include a memory to store a variety of information for configuring individual constituent elements. 
       FIG. 7  is a schematic diagram of a connection module of a lighting apparatus according to an embodiment of the present disclosure. The connection module  451  may include a controller  710 , a driver  720 , a power port  730 , a connection control circuit  735 , an input port  740 , an output port  750 , and an output port  760  to the light emitting module  421 . The controller  710  may provide an infrastructure for controlling the entirety of the lighting apparatus  41  and establishing a connection for data communication with neighboring bridge devices  40  or lighting apparatuses. 
     The controller  710  may control the operation of the light emitting module  421 . The controller may process data received through the input port  740  and driver  720  for operation of the lighting apparatus  41  as well as address assignment and other configuration processes. The controller  710  may store various types of data in the memory  715 , such as an assigned address for the lighting apparatus  41 . 
     The input port  740  may be connected to either the serially connected bridge device  40  or an output port of a different lighting apparatus, such that it can receive a variety of control data and address data. The input port  740  may include one line connected to a ground terminal and two lines used to receive data. 
     The output port  750  may transmit data received through the input port  740  to an input port of a subsequent, serially connected lighting apparatus  42 . The output port  750  may include one line connected to a ground terminal and two lines which may be used to transmit data. 
     The two data lines on the output port  750  may be connected to the two data lines on the input port  740 . For example, a signal path may be provided through the connection module  451  to connect the input port  740  to the output port  750 . The connection control circuit  735  may be positioned between the input port  740  and the output port  750  across the data lines, and configured to control the connection state of the data lines between the input and output ports  740  and  750 . 
     For example, the connection control circuit  735  may be positioned between the input port  740  and the output port  750  of the lighting apparatus  41 , across terminals A and B at the output port  750 . In order to terminate the connection to the next lighting apparatus  42 , the connection control circuit  735  may electrically short circuit the data lines between terminals A and B at the output port  750  based on a control signal from the controller  710 . That is, the difference in voltage between output terminals A and B is no longer present, and therefore, data signals cannot be transmitted through the output port  750  to the subsequent lighting apparatus  42 . The data lines at the input port are not affected by the connection control circuit  735  and data may be received at the input port while the output port is disconnected. Each of the lighting apparatuses  42  to N may operate in a similar manner to control a connection state to a subsequent lighting apparatus. The connection control circuit  735  may be a switch, a diode, a relay, semiconductor devices, or another appropriate electric circuit. The connection control circuit  735  may also be implemented in the controller  710  to disable data output at the output port  750 . 
     A second output port  760  may be provided to connect the connection module  451  to a corresponding light emitting module  421  of the lighting apparatus  41 . The LEDs provided in the light emitting module  421  may be driven by a PWM signal generated by the controller  710 . The PWM signal may be used to dim or otherwise adjust the light output levels of the LEDs. Here, the connection module  451  may also be referred to as a dimming connector. 
       FIG. 8  is a flow chart of a method for controlling a connection module  735  according to one embodiment. In step S 801 , the data connection to a subsequent lighting apparatus may be disconnected in a lighting apparatus. For example, when a data packet is received at a lighting apparatus  41 , the controller  710  of the lighting apparatus  41  may determine whether the data packet includes a command code for initiating address assignment. If the data packet is for initiating address assignment, the controller  710  may transmit the data packet to all of the serially connected lighting apparatuses  42  to N according to the RS-485 communication protocol. The controller  710  of each lighting apparatus  41  to N may then initiate a procedure for address assignment by temporarily severing the data connection to a subsequent lighting apparatus. In order to sever the data connection, the controller  710  may electrically short-circuit the data lines at the output port  750  using the connection control circuit  735  connected between the input port  740  and the output port  750 . In one embodiment, once the data connection to the next lighting apparatus is disconnected, the controller  710  may clear any stored addresses from memory  715 . 
     Thereafter, the bridge device  40  or the lighting controller  20  may transmit a second data packet to the lighting apparatus  41  that includes an address, in step S 802 . The second data packet may be generated after the initiation of the address assignment process. The controller  710  may determine whether the received address should be assigned to the lighting apparatus  41 , in step S 803 . For example, the controller  710  may determine whether an existing address is stored in the controller  710  for the lighting apparatus  41 . If an address is not stored, then the address is needed and the controller  710  processes the second data packet to assign and store the received address for the lighting apparatus  41 , in step S 804 . The controller  710  then reestablishes the data connection to the next lighting apparatus  42  using the connection control circuit  735 , in step S 805 . 
     If it is determined that an address exists, in step S 803 , the controller  710  may open the data connection to the subsequent lighting apparatus  42  using the connection control circuit  735 , in step S 806 . The second data packet including the address is forwarded to the next lighting apparatus  42 , in step S 807 . To reestablish the data connection to the next lighting apparatus  42 , the controller  710  controls the connection control circuit  735  to be in an electrically open state such that the data connection between the input port  740  and the output port  750  is reestablished. The data packets received at the input port  740  may then be transmitted through the output port  750  to the subsequent lighting apparatus  42 . 
     A subsequent data packet received at the lighting apparatus  41  after the address has been assigned and stored in the lighting apparatus  41  may be forwarded to the next lighting apparatus  42 . For example, any data packet received once the address has been assigned may be forwarded to the next lighting apparatus without processing the data packet to assign or store any subsequently received address data. 
     Once the address assignment process has completed, the controller  710  of lighting apparatus  41  may use the assigned address to determine whether a control data received is intended for lighting apparatus  41 . If the address in the received control data matches the stored address, the control data may be processed to control the lighting apparatus  41  based on the received control data. 
     The controller  710  in each lighting apparatus  42  to N may initiate the same process as described above for lighting apparatus  41  to initiate address assignment and to process control data. 
       FIG. 9  illustrates a format of a data packet according to an embodiment of the present disclosure. The data signal transmitted to the lighting apparatuses  41  to N may be configured as a data frame. For example, the data frame may include at least one of a start delimiter field, packet length field, destination address field, source address field, command code field, control value field, checksum field, and/or an end delimiter field. 
     The start delimiter may designate the beginning of a packet frame having a specific purpose, and the end delimiter may designate the end of a packet frame having a specific purpose, such that individual packet frames can be identified. Each of the start delimiter and the end delimiter may have a predetermined value. In  FIG. 9 , the start delimiter is denoted by 0x02 and the end delimiter is denoted by 0x03. 
     Moreover, the start delimiter may designate a start point of a packet frame and may operate as an identifier to identify the corresponding purpose of various packet frames. Therefore, a device that receives the packet frame may extract the start delimiter of the received packet frame to identify a specified purpose of the corresponding packet frame or to recognize the start point of the corresponding packet frame. As a result, the receiving device may accurately extract the necessary information from the received data frame to perform a desired operation. 
     The packet length field may include length information of the corresponding packet frame. In this case, packet length may designate a total packet length from the start delimiter to the end delimiter. Alternatively, the packet length may be a length of the corresponding packet frame located after the packet length field. 
     The destination address field may include destination address information of the corresponding packet frame, and the source address field may include source address information of the corresponding packet frame. If the device associated with the address is a bridge device, the assigned address may be ‘0x0000’. In addition, the destination address may be 2 bytes to designate a destination address (4˜12 bits) and to make a distinction between Mode 0 and Mode 1 using a Most Significant Bit (MSB). For example, Mode 0 may be used to independently control each lighting apparatus (Private Control Mode), and Mode 1 may be used to control one or more lighting apparatus on a group basis (Group Control Mode). 
     The command code field may include a command code corresponding to a purpose of the corresponding packet frame. The command code may correspond to a particular command and indicate the purpose of the corresponding packet frame. For example, the corresponding packet frame information may identify an address assignment type data packet or a control information type data packet using the command code field. The lighting apparatus may perform an operation based on the command code. 
     The control value field may include a specific value indicating attributes of control content defined in the corresponding packet frame corresponding to at least one of the destination address or source address. The control value field may have a value dependent upon the command code information. Moreover, the checksum field may include a checksum for the corresponding packet frame. The checksum may be used to check for errors in the packet frame. 
       FIG. 10  shows information related to command codes contained in a packet frame according to an embodiment of the present disclosure, including exemplary definitions of various command codes and control values. The command codes may be classified into those related to an address assignment function and those related to a control function of the lighting apparatuses. 
     The column labeled ‘CC’ shows command codes which may be included in the CC field in the packet frame, and ‘Value’ designates control values which may be included in the Value field in the packet frame of  FIG. 9 . The column labeled ‘Direction’ shows the direction of data transmission between the bridge device  40  and the lighting apparatus  41  to N. A right arrow indicates data transmission from the bridge device  40  to the lighting apparatuses and a left arrow indicates data transmission from the lighting apparatuses to the bridge device  40 . In addition, the column labeled ‘Function’ corresponds to a title or name of a corresponding command code, and ‘Note’ includes a description of the command code. In  FIG. 10 , a function that includes the term ‘JOIN’ in the ‘Function’ column corresponds to the address assignment process. 
     A JOIN Reset packet frame that includes a command code ‘0xC5’ may be generated at the bridge device  40  or the lighting controller  20  for transmission to the lighting apparatuses  41  to N. The JOIN Reset packet may be used to initiate the address assignment process. This packet may be broadcast to all of the lighting apparatuses  41  to N attached to the bridge device  40 . Upon receipt of the JOIN Reset packet, each lighting apparatus may clear previously stored address information prior to the bridge assigning an address to each lighting apparatus. 
     Upon receiving the JOIN Reset packet, each lighting apparatus may parse the received JOIN Reset packet and remove an address stored in its memory. Moreover, as described with reference to  FIG. 7 , the controller  710  of each of the lighting apparatuses receiving the JOIN Reset packet may control the connection control circuit  735  to disconnect the data path between the input port  740  and the output port  750  of the lighting apparatus  41  to N such that a data connection to a subsequent lighting apparatus is severed. The connection control circuit  735  may disconnect the data path by short circuiting the data lines at the output port  750 . 
     Once the preparation for address assignment has been completed by deleting the address information and disconnecting the data connection to a subsequent lighting apparatus, a new address may be assigned in the lighting apparatus. The bridge device  40  may transmit a JOIN Start packet having a command code ‘0xC1’ to the lighting apparatus  41  which is the first connected in series. Here, because the data connections to subsequent lighting apparatuses have been disconnected in all lighting apparatuses, only the first lighting apparatus  41  connected to the bridge device  40  receives the JOIN Start packet. The JOIN Start packet may indicate the beginning of the address assignment process for the first lighting apparatus  41  in the bridge device  40 . In other words, the bridge device  40  may initiate the address assignment process by transmitting the JOIN Start packet, and the lighting apparatus  41  may initialize the first connection module  451  for address assignment in response to the JOIN Start packet. 
     The first lighting apparatus  41  may parse the JOIN Start packet. Based on the parsed packet, the lighting apparatus  41  may transmit a JOIN Request packet to the bridge device  40 . The JOIN Request packet may serve as an address assignment request packet to the bridge device  40 . The JOIN Request packet may include a command code ‘0xC2’. 
     The bridge device  40 , having received the JOIN Request packet, may register the lighting apparatus  41  and transmits a JOIN Response packet that includes an address. The JOIN Response packet may include a command code ‘0xC3’. The bridge device  40  may also transmit information related to the registered lighting apparatus  41  and corresponding address data to the lighting controller  20  through the gateway  30  for subsequent control of the lighting apparatus  41 . 
     In one embodiment, the address data may be generated at the controller  20 . For example, if the bridge device  40  receives the JOIN Request packet from the lighting apparatus  41 , the bridge device  40  may register the corresponding lighting apparatus  41 , transmit information regarding the registered lighting apparatus  41  to the lighting controller  20  through the gateway  30 , receive address data for the lighting apparatus  41  from the lighting controller  20 , include the received address data in a JOIN Response packet, and transmit the resultant JOIN Response packet to the corresponding lighting apparatus  41 . 
     In this way, in response to the JOIN Response packet that includes the address information from the bridge device  40  (or the lighting controller  20 ), the lighting apparatus  41  may receive and set a new address. The controller  710  then generates a ‘JOIN OK’ packet for transmission to the bridge device  40  indicating completion of the address assignment process. The JOIN OK packet may include a command code ‘0xC4’. The JOIN OK packet may also include an identifier indicating the corresponding lighting apparatus. The identifier corresponding to the lighting apparatus  41  may be a device identifier. 
     Moreover, when the JOIN OK packet is transmitted, the controller  710  of the lighting apparatus  41  may control the connection control circuit  735  to reestablish the data connection to the subsequent lighting apparatus (e.g., lighting apparatus  42 ). The connection control circuit  735  may be controlled to be in an electrically opened state, such that the short circuit between the data lines at the output port  750  is removed. 
     Thereafter, a second JOIN Start packet may be transmitted by the bridge device  40 . The second JOIN Start packet may pass through the first lighting apparatus  41  without address assignment to the second lighting apparatus  42  to initiate the address assignment process. The addresses in each of the lighting apparatuses may be assigned in the same manner as described above with reference to lighting apparatus  41 . 
     The command code may also be used for operational commands and responses. For example, the data packet from the bridge device  40  to the lighting apparatus  41  may be a Control Request packet having a command code ‘0x03’. This data packet may control the lighting apparatus  41  to turn on or off. The data packet may be a Dimming Request packet having a command code ‘0x05’ for controlling a brightness of the LEDs. 
     The data packet may be a Status Request packet having a command code ‘0x04’ for requesting a status from a lighting apparatus. The Status Request packet may request an illumination value from the lighting apparatus. The lighting apparatus may respond with a Status Response packet having a command code ‘0x10’, that includes a value corresponding to the illumination level of the LEDs. 
     A Recover Saved packet may include command code ‘0x2’ and a value 0x00 or 0xFF. If the value in the Recover Saved packet transmitted to a lighting apparatus is 0xFF, the lighting apparatus may recover a previously stored dimming value and turn the lighting apparatus on using this value. If the value is 0x00, the lighting apparatus is turned off. 
     A Set Dimming Speed packet may include a command code ‘0x20’ and values. An Alive Check Request packet and an Alive Check Response packet may include a command code ‘0xFD’. The Alive Check Response packet may respond with a status of the lighting apparatus to the bridge  41 . A Version Request and Version Response packets may include a command code ‘0x30’ and may be used to obtain version information for a particular lighting apparatus. 
       FIG. 11  is a flowchart illustrating a process for address assignment in a lighting apparatus according to one embodiment of the present disclosure. The JOIN Reset packet may be broadcast from the bridge device  1110  to all serially connected lighting apparatuses  1120  to N, in step S 1110 . The process for assigning an address to the first serially connected lighting apparatus may be initiated, in step S 1120 . 
     In step S 1121 , a JOIN Start packet may be transmitted from the bridge device  1110  to the first connection module (CM  1 )  1120  of the first lighting apparatus. The connection module  1120  may respond with a JOIN Request packet, in step S 1122 . The bridge device  1110  registers the first lighting apparatus based on the JOIN Request packet. The bridge device  1110  may transmit a JOIN Response packet that includes a new address to the first connection module  1120 , in step S 1123 . The first connection module  1120  parses the JOIN Response packet for the address and the new address is assigned and stored in the first connection module  1120 . The first connection module  1120  transmits a JOIN OK packet to the bridge, in step S 1124 , once the address has been successfully assigned. The first connection module  1120  then reopens the data connection to the second connection module (CM  2 ) of the next serially connected lighting apparatus, in step S 1125 . 
     A process to assign an address to the second lighting apparatus may be performed, in step S 1130 . The bridge device  1110  may transmit a second JOIN Start packet. The second JOIN Start packet is transmitted through the first connection module  1120  to the second connection module (CM  2 )  1130 . For example, the JOIN Start packet for assigning an address of the second connection module  1130  is not transmitted directly from the bridge device  1110  to the second connection module  1130 , but is transmitted to the second connection module  1130  through the first connection module  1120  of the first lighting apparatus. 
     The process in step S 1130  is completed in the same manner as described with reference to step S 1120  for the first lighting apparatus. For example, a JOIN request, JOIN response, and JOIN OK packets are exchanged between the bridge device  1110  and the second connection module  1130  through the first connection module  1120 , and the connection to a subsequent lighting apparatus is reestablished. 
     During the address assignment process for the second connection module  1130 , the first connection module  1120  may analyze each data packet to determine the intended destination of the packet. For example, the first connection module  1120  may compare the address in the JOIN response packet with the address stored in its memory  715 . If the addresses in the data packets are different than the stored address, the first connection module  1120  may relay the packets to an adjacent device without processing the packets for address assignment. Here, if the data lines are disconnected, the first connection module  1120  may reconnect the data connection to the subsequent lighting apparatus. The process of step S 1130  may be applied in steps S 1140  to S 1150 , to assign an address to the remaining lighting apparatuses  1140  to N. 
       FIG. 12  is a flowchart illustrating a process for address assignment in a lighting apparatus according to one embodiment of the present disclosure. The address assignment process of this embodiment may detect a lighting apparatus that has been replaced after completion of address assignment for all the lighting apparatuses, and assign a new address to the lighting apparatuses. This process may also detect a lighting apparatus which is replaced before completion of the address assignment process for all of the lighting apparatuses. 
     In this embodiment, the JOIN Start packet may be continuously and periodically broadcast to all of the serially connected lighting apparatuses. For example, after addresses have been assigned to all of the lighting apparatuses, the JOIN Start packet may be used to detect any lighting apparatus which may have been replaced. 
     For example, the lighting apparatus corresponding to connection module  1240  may be replaced, requiring a new address. The process as illustrated in  FIG. 12  may detect this replaced lighting apparatus. The JOIN Start packet may be broadcast, in step S 1210 . Upon receiving the JOIN Start packet, transmitted in step S 1210 , the connection manager  1240  of the replaced lighting apparatus may transmit a JOIN Request packet, in step S 1220 . The bridge device  1210  may identify the connection manager  1240  that transmitted the JOIN Request packet as corresponding to the lighting apparatus replaced after completion of a previous address allocation process. 
     If the bridge device  1210  receives the JOIN request packet from the third connection module  1240  in response to the JOIN Start packet transmitted in step S 1210 , the bridge device  1210  may initiate an address assignment process to assign a new address for all lighting apparatuses. For example, the bridge device  1210  may transmit a JOIN Reset packet to all of the connected lighting apparatuses, in step S 1230 . Each of the lighting apparatuses may initialize their respective address data and severs the data connection to a subsequent connection module in response to the JOIN Reset packet. 
     The bridge device  1210  may perform an address assignment process to assign an address to the first lighting apparatus connected in series, in step S 1240 . The bridge device  1210  may issue a JOIN Start packet to connection module  1220 , in step S 1241 . The first lighting apparatus may transmit a JOIN Request packet to the bridge device  1210 , in step S 1242 . The bridge device  1210  may respond with a JOIN Response packet, in step S 1243 . The first connection module  1220  may assign the received address to the first lighting apparatus and may send a JOIN OK packet as a confirmation to the bridge device  1210 , in step S 1244 . The first connection module  1220  may reopen the data connection to the next connection module  1230 , in step S 1245 . Thereafter, the remaining serially connected lighting apparatuses  1230  to N may be reassigned addresses in sequence, in steps S 1250 , S 1260 , S 1270 , and S 1280 , respectively, in a similar manner. Steps S 1203  to S 1280  of this embodiment is the same as steps S 1110  to S 1150 , previously described with reference to  FIG. 11 . 
       FIG. 13  is a flowchart illustrating a process for address assignment in a lighting apparatus according to one embodiment the present disclosure, in which an address is assigned to a lighting apparatus that is newly added after completion of an address assignment for all of the lighting apparatuses. In contrast to the embodiment of  FIG. 12  in which a lighting apparatus that is replaced is detected, in this embodiment a newly added lighting apparatus may be detected. For example, an address assignment process is initiated after detection of a newly added N-th connection module (CM N) N. Here, the addition of connection module N is detected after address assignment has been completed up to the fourth connection module (CM 4 )  1350 . 
     The bridge device  1310  may periodically transmit a JOIN Start packet upon completion of address assignment in order to detect a presence or absence of a newly added lighting apparatus, in step S 1310 . The bridge device  1310  may transmit the JOIN start packet to all previously connected devices, e.g., up to connection module  1350 . If a fifth connection module  1360  is added after the execution of step S 1310 , the connection module  1360  may receive the next or subsequent periodic JOIN Start packet, in step S 1320 . 
     In response to receiving the JOIN Start packet, the connection module  1360  may transmit a JOIN request packet to the bridge  1310 , in step S 1330 . The bridge device  1310  may determine that the connection manager N has been newly added based on the received the JOIN Request packet. The bridge device  1310 , having recognized that connection module N corresponds to a newly added lighting apparatus, transmits a JOIN reset packet to all connected lighting apparatuses, in step S 1340 . 
     The address for each lighting apparatus  1320  to N may be assigned in sequence, in steps S 1350  to S 1390 . Steps S 1350  to S 1390  are the same as steps S 1120  to S 1150  and S 1240  to S 1280 , previously described with reference to  FIGS. 11 and 12 , respectively. 
     In certain embodiments, the address for the newly added or replaced lighting apparatus may be assigned without broadcasting the JOIN Reset packet. For example, in step S 1220  of  FIG. 12 , the connection manager  1240  may reset the stored address and disconnect the data connection to a subsequent lighting apparatus. Thereafter, a JOIN Response packet may be transmitted from the bridge  1210  to connection manager  1240 . For example, because the JOIN Reset packet is not transmitted, connection managers  1220  and  1230  are not controlled to disconnect the data connection to a subsequent device. Hence, the JOIN Response packet may be transmitted to the third connection manager  1240 . 
     Upon receipt of the JOIN Response packet, the connection manager  1240  may process the packet to assign and store the received address, and transmit a JOIN OK packet to the bridge device  1210 . The newly added connection manager  1240  may then establish a data connection to the subsequent connection manager (e.g.,  1250 ). In this embodiment, the bridge device  1210  may assign the address previously assigned to the lighting apparatus to the replaced lighting apparatus. The bridge device  1210  may then continue to periodically transmit a JOIN Start packet to detect replaced lighting apparatuses. A similar process may be applied to the embodiment of  FIG. 13  to detect and assign an address new lighting apparatuses, without reassigning an address to all connected lighting apparatuses. 
     Through the above-mentioned steps, one bridge device and all lighting apparatuses connected thereto may perform real-time automatic address assignment even when an additional lighting apparatus is replaced or added. The addresses may be newly assigned without the need for additional requests from a user. 
       FIG. 14  is a flowchart illustrating a method for controlling a lighting system according to an embodiment of the present disclosure. A lighting apparatus  41  to N may initialize each port to perform a control operation, in step S 1410 . If each port is initialized, the lighting apparatus  41  to N may initialize a timer, in step S 1420 . The timer initialization may be synchronized with the bridge device  40  to receive each packet frame. 
     The lighting apparatus  41  to N may initialize the UART and the RS-485 port, in step S 1430 . The RS-485 port may designate an output port in the connection module  451  to N″ of each lighting apparatus  41  to N for communication with the bridge device  40 . A watchdog is reset, in step S 1440 , and a switching-mode power supply (SMPS) is checked, in step S 1450 . For example, the SMPS may indicate whether the bridge device  40  or each lighting apparatus  41  to N is powered on. 
     Upon receiving a dimming value from the bridge device  40 , each lighting apparatus  41  to N may parse the corresponding dimming value, and determine whether the parsed dimming value is identical to the current dimming value, in step S 1460 . If the current dimming value is determined to be different from the requested dimming value, in step S 1460 , the current dimming value is changed based on the requested dimming value, in step S 1470 . A tick operation for the light emitting module may be performed in response to the new dimming value, in step S 1480 , to change the light output. If necessary, each lighting apparatus  41  to N may pop the UART queue, in step S 1490 . The packet handler may request specific information dependent upon the popped-up UART queue, in step S 1500 . 
     As apparent from the above description, in the lighting system as broadly described and embodied herein, a unique address may be automatically assigned to each lighting apparatus for use in the lighting system. The lighting apparatuses having the unique addresses may be controlled together as a group or independently. Moreover, a simple circuit configuration may be achieved according to the disclosed connection schemes of the lighting apparatuses for automatically assigning a unique address to each lighting apparatus. 
     As broadly described and embodied herein, a method for controlling a lighting apparatus in lighting system may include transmitting a first packet for initializing to a plurality of lighting apparatuses, wherein each lighting apparatus releases a connection with a subsequent lighting apparatus, and transmitting a second packet including address data to the lighting apparatus, wherein the lighting apparatus decodes and stores the address data from the second packet and then connects with a subsequent lighting apparatus. 
     The method may further include transmitting a third packet including address data to the lighting apparatus. Each packet may include a packet identifier for identifying a type of corresponding packet. 
     The lighting apparatus may determine whether address data is previously stored. The lighting apparatus controls a transfer of the address data to a subsequently connected lighting apparatus if the address data is previously stored. 
     The method may further include receiving a packet to request an address from each lighting apparatus. The method may further include determining the packet including a request for assigning an address from the lighting apparatus in order to transmit the first packet. The method may further include receiving a packet including a response indicating address assignment completion from the corresponding light emitting part. Moreover, the method may further include transmitting a fourth packet including control data to the lighting apparatus being assigned address. 
     In one embodiment, a method for controlling a plurality of lighting apparatuses for use in a lighting system may include initializing each lighting apparatus, sequentially assigning an address to the individual lighting apparatus, and controlling the lighting apparatus being assigned the address, wherein the step of initializing includes releasing a connection with a subsequent lighting apparatus. The releasing a connection with the subsequent lighting apparatus may be performed by electrically connecting a plurality of ports in order to transfer data to a subsequent lighting apparatus. 
     In one embodiment, a method for controlling a plurality of light emitting parts for use in a light control apparatus may include a) receiving a request from any one of the plurality of lighting apparatuses, b) transmitting a first packet for initializing all lighting apparatuses, c) transmitting a second packet for assigning an address of the plurality of lighting apparatus, and d) controlling the lighting apparatus on the basis of the assigned address of corresponding lighting apparatus. The step (a) may be performed if a lighting apparatus is inserted into the plurality of light emitting parts or is added thereto. 
     A lighting system as broadly described and embodied herein may include a plurality of lighting apparatuses, at least one bridge device coupled to the plurality of lighting apparatuses, and a lighting controller coupled to the at least one bridge device for controlling the lighting apparatuses. One of the at least one bridge device or the controller may generate address data for assigning an address to one of the plurality of lighting apparatuses. The plurality of lighting apparatuses may include an LED module, a connection circuit configured to control a connection between the at least one bridge device and the plurality of lighting apparatuses, and a controller configured to control the connection circuit based on the address. 
     The connection circuit may include an input port to receive the data from the bridge device, an output port to relay the address data to another lighting apparatus, and a switch to electrically connect or disconnect the connection between the input port and the output port. At least two data lines may be connected between the input port and the output port, and the switch may be positioned to create a short circuit between the data lines at the output port to disconnect the connection between the input and output connectors. 
     The controller may control the switch to electrically connect or disconnect the connection based on the address data. The controller may determine whether the address is needed, and control the switch to disconnect the connection to prevent the address data from being transferred to a subsequent lighting apparatus if the address data is needed and control the switch to connect the connection to transfer the address data to a subsequent lighting device if the address is not needed. 
     The bridge device may be configured as a master and the plurality of lighting apparatuses are configured as a slave. The bridge device may be connected in series to the lighting apparatuses according to a RS-485 communication protocol. The plurality of lighting apparatuses may include a driver configured to transmit and decode data according to the RS-485 communication protocol. Moreover, the bridge device may transmit information corresponding to the assigned address to the controller through the gateway. The bridge device may be connected to the gateway according to a ZigBee communication protocol and the gateway may be connected to the controller according to a TCP/IP protocol. 
     In one embodiment, the lighting system may include a first lighting apparatus, a second lighting apparatus connected to the first lighting apparatus in series, and a bridge device coupled to the first lighting apparatus in series and configured to send an address to the first and second lighting apparatuses. The first lighting apparatus may include a first light source, a first input connector coupled to the bridge device and a first output connector, and a first control circuit to control a connection between the input connector and the output connector. The second lighting apparatus may include a second light source, a second input connector coupled to the output connector of the first lighting apparatus and a second output connector, and a second control circuit to control a connection between the second input connector and the second output connector. After the first control circuit disconnects the connection between the first input and output connectors, the bridge device may send an address to the first lighting device. Moreover, the first control circuit determines whether an assignment of the address is needed for the first lighting apparatus, and if the assignment is not needed, the first control circuit may connect the first input and output connectors to allow the address to be sent to the second control circuit. 
     The connector circuits may include a switch or relay. The switch or relay may be positioned at the output connectors and configured to short circuit a data line at the output connector to disconnect the connection between the input and output connectors. If the assignment is needed, the first control circuit may assign the first address to the first lighting apparatus. 
     The lighting system may include a controller coupled to the bridge device and configured to control the first lighting apparatus based on the address assigned to the first lighting apparatus. The bridge device may be connected in series to the lighting apparatuses according to a RS-485 communication protocol. In this embodiment, a gateway may be communicatively coupled between the bridge device and the controller, wherein the bridge device transmits the address for the lighting apparatuses to the controller through the gateway. The bridge device may be connected to the gateway according to a ZigBee communication protocol and the gateway may be connected to the controller according to a TCP/IP protocol. Moreover, the address may be generated in the bridge device or the controller. 
     In one embodiment, a lighting system may include a first lighting apparatus, a second lighting apparatus connected to the first lighting apparatus in series, a bridge device coupled to the first lighting apparatus in series, and a controller coupled to the at least one bridge device for controlling the first and second lighting apparatuses, wherein one of the at least one bridge device or the controller generates an address for assignment to one of the plurality of lighting apparatuses. The first lighting apparatus may include a first LED module, a first input connector coupled to the bridge device and a first output connector, and a first control circuit to control a connection between the input connector and the output connector. The second lighting apparatus may include a second LED module, a second input connector coupled to the output connector of the first lighting apparatus and a second output connector, and a second control circuit to control a connection between the second input connector and the second output connector. The first and second control circuits may include a switch positioned at the output connectors to short circuit a data line for disconnecting the connection between the input and output connectors based on the address. 
     In one embodiment, a lighting system may include a plurality of lighting devices, an address assigning device configured to assign an address to each light emitting module, and a gateway configured to communicate with the address assigning device, and a control unit configured to control the connector. Each lighting device may include a light emitting module, a connector configured to connect or disconnect among the address assigning device, corresponding light emitting module, and a subsequent lighting emitting module. 
     Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.