Patent ID: 11863146
Assignee: WHELEN ENGINEERING COMPANY, INC.
Field: Control (Instruments)
Classification: CPC G  H | IPC H

Claim 11:
12. A synchronization method, comprising:
reading, by a first node including a first emergency sound generator, first tone information and first volume level information both corresponding to the first emergency sound generator from at least one memory coupled; and
generating, by the first node, a first tone signal having a voltage level based on the first tone information and the first volume level information;
reading, by a second node including a second emergency sound generator, second tone information and second volume level information both corresponding to the second emergency sound generator from the at least one memory; and
generating, by the second node, a second tone signal having a voltage level based on the second tone information and the second volume level information; and
synchronizing, by one or more processors, the first tone signal and the second tone signal by setting a phase offset between the first tone signal and the second tone signal to be the same,
wherein each of the first tone information and the second tone information includes data of frequency variation over a predetermined period, and each of the first volume level information and the second volume level information includes data of volume level variation over the predetermined period
wherein to synchronize the first tone signal and the second tone signal, the first node and the second node each determine a common global time based on one or more synch messages transmitted from a main node;
wherein the first node is further configured to:
receive a first time at which the main node transmits a first synch message including the first time;
determine a second time at which the first node receives the first synch message;
determine a difference between the first time and the second time;
receive a third time at which the main node transmits a second synch message including the third time;
determine a fourth time at which the first node receives the second synch message; and
determine the global time by adding the difference to the third time.