Hi Zhang, > that is to say this is the time synchronization between the sender and > receiver , not the whole network ?
Correct. > i have seen the TimeSyncAMSend, when you send a packet , you shou give an > parameter "event_time" in the command send . i can't understand the function > of the parameter . it says that "parameter holds the time of some event as > expressed in the local clock of the sender." , what dose the "some event " > mean ? what should i set it to ? > when the receiver receive the packet sended using the interface > TimeSyncAMSend , what does it use the parameter event_time do ? can you > explain how does the sender and the receiver realize time synchronization > detailedly ? -:) i am so sorry , i still can't understand . Say you have dectected light on node A in an antitheft application and would like to inform node B (which maybe correlates events and ther detection times from different nodes) - Light detected by node A at time 1000. At the same instant the local time on node B was 2000. Node B does not know of the detection. - Node A decides to inform node B about the "intruder", so it sends a message with TimeSyncAMSend. The message was sent (the first bit of it was in the air) at 1150. - The message in the air contains the value 150 (the time offset between the event time and transmission time). The reception time on node B is 2150. - When you call TimeSyncPacket on node B to get the event time, then that will return 2150-150 = 2000, i.e. the time of the detection as expressed in the local clock of node B. > is there some time synchronization which supports rf230 implemented in > tinyo-2.x ? FTSP will use it. You can build your own protocol around the sender-receiver time sync primitive. > Collection Tree Protocol . it is a muliti-hop route protocol . They are unrelated, although you could do some timestamping as in the elapsed time on arrival paper by B. Kusy et al. Miklos _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
