Method and apparatus for providing a message sequence count in a security system

Abstract

The present invention is a security system and method of operating the security system which includes a wireless transmitter, a wireless receiver in wireless communication with the wireless transmitter, and a control panel connected to the wireless receiver. The transmitter transmits a wireless message, which includes a unique transmitter identification number, a status portion with a plurality of status bits, and a sequence count which it increments only when any one of the status bits changes. The receiver receives the wireless message, converts the wireless message to a digital message, and then sends the digital message to the control panel. The control panel then processes the digital message by first extracting the sequence count and transmitter identification number from the message. A previous sequence count associated with the transmitter identification number is retrieved from memory, and the sequence count from the message is compared with the previous sequence count retrieved from the memory. If the sequence count from the message is less than the previous sequence count, then the control panel ignores the message. If, however, the sequence count from the message is not less than the previous sequence count, then the control panel processes the message (i.e. the status bits) and replaces the previous sequence count in memory with the sequence count from the message.

What is claimed is:  
     
         1 . In a security system comprising a wireless transmitter, a wireless receiver in wireless communication with the wireless transmitter, and a control panel connected to the wireless receiver, a method of operating the security system comprising the steps of: 
 a. the transmitter transmitting a wireless message, the wireless message comprising a unique transmitter identification number, a status portion comprising a plurality of status bits, and a sequence count;    b. the receiver receiving the wireless message, converting the wireless message to a digital message and sending the digital message to the control panel;    c. the control panel processing the digital message by the steps of: 
 i. extracting the sequence count and transmitter identification number from the message;  
 ii. retrieving from memory a previous sequence count associated with the transmitter identification number;  
 iii. comparing the sequence count from the message with the previous sequence count from memory; 
 1. if the sequence count from the message is less than the previous sequence count, then ignoring the message; and  
 2. if the sequence count from the message is not less than the previous sequence count, then processing the message and replacing the previous sequence count in memory with the sequence count from the message.  
 
   
     
     
         2 . The method of  claim 1  wherein the step of transmitting a wireless message comprises the steps of: 
 i. determining if any of the status bits in the status portion of the wireless message has changed from the previously transmitted message;  
 ii. if any of the status bits has changed, then incrementing the sequence count from the previously transmitted message, and  
 iii. if any of the status bits has not changed, then using the same sequence count as in the previously transmitted message.  
 
     
     
         3 . A security system comprising: 
 a. a wireless transmitter adapted to transmit a wireless message comprising a unique transmitter identification number, a status portion comprising a plurality of status bits, and a sequence count;    b. a control panel; and    c. a plurality of wireless receivers connected to the control panel and in wireless communication with the wireless transmitter, wherein each of the receivers comprise means for receiving the wireless messages from the transmitter, converting the wireless messages to digital messages and sending the digital messages to the control panel; and    d. wherein the control panel comprises: 
 i. means for extracting the sequence count and transmitter identification number from the message;  
 ii. means for retrieving from memory a previous sequence count associated with the transmitter identification number;  
 iii. means for comparing the sequence count from the message with the previous sequence count from memory, adapted to 
 1. if the sequence count from the message is less than the previous sequence count, then ignore the message; and  
 2. if the sequence count from the message is not less than the previous sequence count, then process the message and replace the previous sequence count in memory with the sequence count from the message.  
 
   
     
     
         4 . A method of transmitting a wireless message in a security system comprising the steps of: 
 a. generating a wireless message, the wireless message comprising a unique transmitter identification number, a status portion comprising a plurality of status bits, and a sequence count;    b. determining if any of the status bits in the status portion of the wireless message has changed from the previously transmitted message;    c. if any of the status bits has changed, then incrementing the sequence count from the previously transmitted message;    d. if any of the status bits has not changed, then using the same sequence count as in the previously transmitted message; and    e. transmitting the generated wireless message.    
     
     
         5 . A wireless transmitter for use in a security system comprising: 
 a. means for generating a wireless message, the wireless message comprising a unique transmitter identification number, a status portion comprising a plurality of status bits, and a sequence count;    b. means for determining if any of the status bits in the status portion of the wireless message has changed from the previously transmitted message;    c. means for incrementing the sequence count from the previously transmitted message if any of the status bits has changed;    d. means for using the same sequence count as in the previously transmitted message if any of the status bits has not changed; and    e. means for transmitting the generated wireless message.    
     
     
         6 . A method of a control panel processing a message from a transmitter in a security system, the message comprising a unique transmitter identification number, a status portion comprising a plurality of status bits, and a sequence count, the method comprising the steps of: 
 i. extracting the sequence count and transmitter identification number from the message;    ii. retrieving from memory a previous sequence count associated with the transmitter identification number;    iii. comparing the sequence count from the message with the previous sequence count from memory; 
 1. if the sequence count from the message is less than the previous sequence count, then ignoring the message; and  
 2. if the sequence count from the message is not less than the previous sequence count, then processing the message and replacing the previous sequence count in memory with the sequence count from the message.  
   
     
     
         7 . A control panel for use in a security system comprising: 
 i. means for extracting a sequence count and a transmitter identification number from a received message;    ii. means for retrieving from memory a previous sequence count associated with the transmitter identification number;    iii. means for comparing the sequence count from the message with the previous sequence count from memory, adapted to 
 1. if the sequence count from the message is less than the previous sequence count, then ignore the message; and  
 2. if the sequence count from the message is not less than the previous sequence count, then process the message and replace the previous sequence count in memory with the sequence count from the message.