| 摘要 |
Data is communicated between a central control unit that generates a sequence of periodic control messages and at least one traffic signal controller or sensor that is arranged to respond to the sequence of periodic control messages by generating a series of periodic reply messages. A first control message packet is received over the digital packet based network at a first control message arrival time. The packet contains data for a first control message and the data for the first control message is stored. A first periodic control message is output to the or each traffic signal controller or sensor at a delay after the arrival time corresponding to a predetermined buffer period. A second control message packet containing data for a second control message is received over the digital packet based network at a second control message arrival time and the data for the second control message is stored. A second periodic control message is output at a delay after outputting of a first control message based on a predetermined periodic interval. |
