Abstract:
An apparatus for restoring network information for a home network system and a method thereof are disclosed. The apparatus includes at least one slave having means for communicating with an external appliances; a master having means for communicating with the slave, checking a state of the slave, storing state information of the slave, and providing the state information to the slave when the slave is reset; and a home network unit connecting the communication means of the master and the slave to form a network of the master and the slave.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Reissue application of U.S. application Ser. No. 10/790,258, filed Mar. 2, 2004, now U.S. Pat. No. 7,499,978, issued Mar. 3, 2009, which claims the benefit of a foreign priority application filed in Korea as Serial No. 10-2003-0013149 on Mar. 3, 2003. This application claims priority to both of the prior applications, and the disclosures of the prior applications are considered part of (and are incorporated by reference in) the disclosure of this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a home network system, and more particularly, to an apparatus for restoring network information for a home network system and a method thereof. 
     2. Description of the Related Art 
     Currently, a home network system have been commercialized for the pursuit of convenience for control, monitoring, etc., of home appliances indoors or outdoors. 
     In the home network system, it is essential to construct communication lines for exchanging signals among the home appliances and a network controller for controlling the home appliances. 
     The home network may be constructed using separate communication lines, but it is preferable to construct the home network using power lines for supplying a power in the home. 
     As the technology in this field has been greatly developed, the home network system will adopt a communication method using the power line in future. 
     Although a separate appliance may be adopted as a network controller, the system may be constructed in a manner that any home appliance, which has a display function and connects to the Internet, such as an Internet TV, a personal computer, an Internet refrigerator, etc., is determined as a network controller, i.e., a master, and other home appliances are determined as slaves. 
     For example, as shown in  FIG. 1 , in the case that a home network is constructed among a TV (e.g., a digital TV), a washing machine, a microwave oven, an air conditioner, etc., the TV may be determined as a master and the washing machine, the microwave oven, the air conditioner, etc., may be determined as slaves. 
     The master and the slaves are connected to power-line communication modems, respectively, and the power-line communication modems are connected to outlets corresponding to power-line nodes A, B, C and D, so that the home network system is constructed. 
     Now, a communication process performed between the master and the slaves in the home network system as constructed above will be explained. 
     First, in the case of a normal communication as shown in  FIG. 2a , the master requests a predetermined command to the slaves to start the communication, and the slaves respond to the master to complete the communication. 
     Meanwhile, if an error occurs during the communication as shown in  FIG. 2b  after the master requested the command to the slaves, the slaves fail to respond to the master. In this case, the master waits for a response from the slave for a predetermined time, and if no response is received after the predetermined time, the master re-requests the command to the slaves. If the slave responds to the master at that time, the communication is completed. 
     In the home network system, the master, e.g., the TV, controls various functions of the slaves including an on/off control of the power supplied to the slaves by a home network control program. The master also controls the registration and management of new home appliances, gives IDs for data communication to the slaves, and displays a picture for controlling the registered appliances. 
     When the power is supplied normally, the master and the slaves perform their normal operations. However, if slaves are reset due to an instantaneous power failure or any abnormal operation of the slaves and thus the slaves lose the operation-related network information, the slaves fail to remember their operation states before they are reset, and thus cannot perform their corresponding operations. 
     Therefore, when the power is supplied after the power failure, a user must reset the operation-related network information through the master or the slaves. 
     As described above, the conventional home network system has the drawbacks in that if the network information related to the operation of the slaves is lost due to an instantaneous power failure or an abnormal operation of the slaves, the user must reset the network information, and this causes inconvenience to the user. Also, as the number of slaves increases, the time required for resetting the slaves also increases. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to solve the problems involved in the related art, and to provide an apparatus for restoring network information for a home network system and a method thereof which can restore the network information of the slaves lost due to an instantaneous power failure or abnormal operations of the slaves. 
     In one aspect of the present invention, there is provided an apparatus for restoring network information for a home network system comprising at least one slave having means for communicating with an external appliances; a master having means for communicating with the slave, checking a state of the slave, storing state information of the slave, and providing the state information to the slave when the slave is reset; and a home network unit connecting the communication means of the master and the slave to form a network of the master and the slave. 
     In another aspect of the present invention, there is provided a method of restoring network information for a home network system comprising the steps of periodically checking a state of at least one slave connected by a network; storing state information of the slave; checking whether the slave is reset, and transmitting the state information of the slave when the slave is reset. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a block diagram of a general home network system. 
         FIGS. 2a and 2b  are views explaining a conventional communication process performed in the home network system of  FIG. 1 . 
         FIG. 3  is a block diagram illustrating the construction of an apparatus for restoring network information for a home network system according to the present invention. 
         FIG. 4  is a flowchart illustrating a method of restoring network information for a home network system according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts. 
     Hereinafter, an apparatus for restoring network information for a home network system according to the preferred embodiment of the present invention will be described with reference to the accordingly drawings. 
       FIG. 3  is a block diagram illustrating the construction of an apparatus for restoring network information for a home network system according to the present invention.  FIG. 4  is a flowchart illustrating a method of restoring network information for a home network system according to the present invention. 
     As shown in  FIG. 3 , the apparatus for restoring network information for a home network system according to the present invention includes slaves  31 , 32  and  33  having RS-232C ports, a master for storing and updating network information of the slaves  31 , 32  and  33  in a non-volatile memory, checking whether the slaves  31 , 32  and  33  are reset, and restoring the network information of the corresponding slave stored in the non-volatile memory if any one of the slaves  31 , 32  and  33  is reset, and power-line communication modems  35 , 36 , 37  and  38  for a network communication between the master  34  and the slaves  31 , 32  and  33 . 
     In this case, the master  34  includes a non-volatile memory, that is an EEPROM (erasable and programmable read only memory)  342  for maintaining the stored data irrespective of the power failure, a CPU  341  that performs a basic control operation of the home networking including giving IDs to the slaves, monitoring and controlling of the operation state, storing network information such as the control, monitoring, etc., of home appliance in the EEPROM  342 , and restoring the network information of the slave when the power is supplied again after the reset of the slave, and a DART (Universal Asynchronous Transmitter/Receiver)  343  and an RS-232C port  344  for the CPU  341  to perform a network communication through a power-line communication modem. 
     A method of restoring the network information performed by the apparatus of  FIG. 3  according to the present invention will now be explained with reference to  FIG. 4 . 
     First, the master  34 , that is the TV, is connected to the power line through the RS-232C port  344  and the power-line communication modern  38 , and the slaves  31 , 32  and  33  are also connected to the power lines through the RS-232Cs port and the power-line communication modems  35 , 36  and  37 . 
     The master  34  communicates with the slaves, registers the slaves by giving IDs to the slaves, and checks the operation states of the slaves. 
     Then, the master  34  controls the slaves according to a user&#39;s control command (step S 41 ). 
     Specifically, the master  34  stores and updates by slaves the network information related to the control and the operation states of the slaves in the EEPROM  342  (step S 42 ). 
     In this case, the network information related to the control and the operation states of the slaves includes control information inputted by the user, monitoring information and information related to the operation state of the slaves. The update of the network information is performed whenever the control information, the monitoring information or the operation-state-related alarming information is inputted. 
     Then, the master  34  cheeks whether the slaves  31 , 32  and  33  are reset due to the power failure or an abnormal state of the slaves S 43 . 
     At this time, the master  34  grasps whether the slaves  31 , 32  and  33  are reset in a manner that the master  34  periodically checks the states of the slaves  31 , 32  and  33 , and the slaves  31 , 32  and  33  periodically inform their states to the master  34 , too. 
     If all or some of the slaves  31 , 32  and  33  are reset due to the power failure or their abnormal states as a result of checking, the master  34  retrieves the network information stored in the EEPROM  342 . 
     Then, the master  34  transmits the network information related to the operation states before the power failure to the reset slaves. 
     Therefore, the reset slaves, which received the network information from the master  34 , are restored to their original states and perform their operations. 
     For example, it is assumed that all of the slaves  31 , 32 , and  33  are reset due to the power failure while a washing machine  31  performs a rinsing operation. If the power is supplied again, the washing machine  31  receives the network information from the master, which corresponds to a command for the washing machine  31  to perform the rinsing operation. 
     Consequently, after the power is supplied again, the washing machine  31  performs the rinsing operation according to the network information related to the latest state of the washing machine receives from the master  34 . 
     If the network information related to the latest state is not transmitted from the master  34 , the washing machine  31  does not resume the operation unless the user inputs a new command. 
     After the slaves  31 , 32  and  33  are restored to their latest operation states, the master  34  prepares for a further possible reset by repeating the steps of storing and updating of the network information. 
     As described above, the apparatus for restoring network information for a home network system and the method thereof according to the present invention has the effects in that it restores the slaves to their latest states and enables the slaves to perform their operations by storing the states of the slaves even if the slaves are reset. Therefore, it is not continue required for the user to set the operations of the slaves if the slaves are reset, and this provides convenience in use. 
     The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.