Lighting control protocol

Abstract

A digital lighting control network protocol with forward and backward frames, each of the frames including an error check code. A no-acknowledgment (NAK) signal is sent from a receiving node to a transmitting node responsive to the error check code. An interface circuit of the receiving node may include an energy storage section to store at least some energy from the network while receiving digital signals, and an output section to transmit digital signals to the network using the stored energy. The interface circuit may also include a high voltage buffer circuit. The transmitting node may send forward frames to receiving nodes based on device type.

1 . A method comprising:
 receiving a forward frame transmitted by a transmitter via a two-wire connection, the forward frame including a payload, stop bits;
 altering a state of an electrical load in response to the received frame if no error is detected; and 
   transmitting a no-acknowledgement (NAK) signal to the transmitter if an error is detected.   
     
     
         2 . The method of  claim 1 , wherein receiving the forward frame comprises receiving a forward frame including error check information to allow detection of an error in the received forward frame. 
     
     
         3 . The method of  claim 2 , wherein the error check information includes an error code. 
     
     
         4 . The method of  claim 1 , wherein transmitting a no-acknowledgement signal comprises transmitting a no-acknowledgement signal upon detection of an error in a payload of the forward frame, a reception error, or a timeout error. 
     
     
         5 . The method of  claim 2 , wherein transmitting the signal comprises asserting a dominant bit as a no-acknowledgement pulse on a data line during a period of time corresponding to the stop bits. 
     
     
         6 . The method of  claim 5 , wherein asserting the dominant bit comprises shorting a buss of a network to cause a voltage fluctuation. 
     
     
         7 . The method of  claim 1 , further comprising transmitting a backward frame to the transmitter upon receiving the forward frame. 
     
     
         8 . The method of  claim 1 , wherein:
 the forward frame is transmitted via a lighting control network that utilizes the two wire connection and bi-phase coding; and
 the forward frame includes a start bit, an address byte, and a data byte. 
   
     
     
         9 . A method comprising:
 transmitting a forward frame to a receiver via a two-wire connection, the forward frame including a payload and stop bits;   receiving a no acknowledgement (NAK) signal from the receiver indicating that there is an error in the payload.   
     
     
         10 . The method of  claim 9 , wherein receiving the signal comprises receiving a dominant bit as a no-acknowledgement pulse on a data line during a period of time corresponding to the stop bits. 
     
     
         11 . The method of  claim 10 , further comprising retransmitting the forward frame to the receiving upon receiving the signal. 
     
     
         12 . The method of  claim 11 , further comprising retransmitting the forward frame a number of times up to a threshold number of times. 
     
     
         13 . The method of  claim 12 , further comprising sending an error message to an operator of a network if the threshold number of times is reached. 
     
     
         14 . The method of  claim 9 , further comprising transmitting a backward frame to the transmitter upon receiving the forward frame. 
     
     
         15 . The method of  claim 9 , wherein:
 the forward frame is transmitted via a lighting control network that utilizes the two wire connection and bi-phase coding; and   the forward frame includes a start bit, an address byte, and a data byte.