Patent Publication Number: US-7590457-B2

Title: Method for bonding a lighting device to a lighting system while using wireless communication

Description:
FIELD OF THE INVENTION 
   The invention relates to a method for bonding a lighting device to a lighting system while using wireless communication as described in the preamble of claim  1 . 
   BACKGROUND OF THE INVENTION 
   A slave controller having stored therein an identification of a system will respond to instructions for controlling a light emitter of the device only if the slave controller can positively confirm that said instructions are received from the master controller of the system. 
   With the prior art a problem arises when a slave controller of a lighting device contains a system identification and one wants to bond the lighting device to a different system, with the lighting device being moved geographically or not. For security reasons access to the slave controller will be limited such, that resetting of a stored system identification to a default value is prohibited. Instead one could conceive a method in which identification numbers or labels are applied invisibly from the outside to a lighting device, which, with some effort, could be read by a user and then entered into the master controller of a different system to bond it to the different system. One could also store such unique numbers of lighting devices on a memory disc, or on a server of an Internet site. These approaches require time consuming and tedious operations for reading, storing and monitoring of such unique number. Such drawbacks are more serious in case many lighting devices must be allocated from one system to a different system or to different systems and/or the lighting devices are to be spread over several geographically distant locations. 
   OBJECT OF THE INVENTION 
   It is an object of the invention to solve the drawbacks of the prior art as described above. 
   SUMMARY OF THE INVENTION 
   The above object of the invention is achieved by providing a method as described in claim  1 . 
   With the method according to the invention it is made possible to bond a lighting device to a lighting system, even if the slave controller of the lighting device has stored therein an identification of a different system. There is no need to keep track of lighting devices and unique numbers allocated to them. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will become more gradually apparent from the following exemplary description in connection with the accompanying drawing. In the drawing: 
       FIG. 1  shows a flow chart of an example of the method according to the invention. 
   

   DETAILED DESCRIPTION OF EXAMPLES 
   The flow chart shown in  FIG. 1  applies to a lighting system (not shown) comprising a master controller and a plurality of lighting devices, with each lighting device comprising a slave controller. A slave controller may store an identification (ID) of the lighting system and the master controller may store identifications of several slave controllers. With such identifications being stored in the master controller and slave controllers, the master controller can then control the lighting devices to selectively turn them on or off or to dim them. 
   The flow chart shown in  FIG. 1  represents a procedure or a method which is entered by a slave controller of a lighting device when the slave controller gets powered. The method is contained between a terminator “BEGIN”  2  down to a terminator “END”  4 . 
   As indicated by decision block  6 , the slave controller starts with checking if it has stored a system identification (ID) already. If the slave controller does not contain such an ID the flow terminates at terminator  4 . Apparently the slave controller is alike green or new. The slave controller will just wait for a request for communication received from a master controller to bond (associate) the slave controller to the master controller. 
   If, according to decision block  6 , the slave controller decided that it contains a system identification (ID), the slave controller will try to establish a communication with a master controller of the system which is associated with the stored ID, as indicated by block  8 . 
   If the slave controller contains an ID and a master controller associated with the same ID responds the flow terminates at terminator  4 . 
   According to the invention if the slave controller contains an ID but it is unable to find or to communicate with a master controller of a system associated with said ID, as indicated by decision block  10 , the slave controller proceeds to block  12 . 
   According to flow block  12 , a security level of a security procedure is lowered for allowing access from the outside for changing the stored ID. The security procedure could be bypassed as a whole. In general a communication with such lowered security level could be indicated as an unsecured communication. 
   Further according to flow block  12 , a time window is set or initiated. It is only during said window that a lowered security level for access from the outside is allowed. 
   During the time window the slave controller monitors the receiving of a clear ID message from the outside, as indicated by decision block  14 . Said message indicates that upon its receipt the slave controller is allowed to clear the ID stored by it, as indicated by block  16 . After executing the clearing of the ID the flow terminates at terminator  4 . 
   If, as indicated by decision block  18 , the clear ID message is not received yet at the end of the time window the flow terminates at terminator  4 . 
   Although not shown in detail in the flow chart of  FIG. 1 , it is noted that the method as described can be made more sophisticated, in that several time windows are used during which different security levels are used. Preferably the number of windows is limited, e.g. to three. 
   It is noted that in stead of clearing a system ID stored in a slave controller a flag could be set indicating that the slave controller is ready to receive and store a system ID. The slave controller could operate to remove such flag if it did not receive a system ID to be stored by it. The slave controller could remove such flag also if the received ID is identical to the stored ID.