| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a multiplex transmission device for vehicles that reduces bus occupancy rate of data and efficiently transmits data of plural communication units. SOLUTION: In each of units 1a, 1b and 1c connected to a bus 3, a data transmission control part 23a judges whether or not there is any change in each vehicle data consisting of plural kinds of data and sets in a communication frame in turn updated or data before updating data depending on whether or not there is any judged change in data. An update bit setting part 25a assignes each information for indicating whether or not there is updated data to each data and sets it in the communication frame. A transmission and reception part 21a transmits the communication frame including each set data and each set information for indicating the presence or absence of an update to other communication unit and receives the communication frame from other communication unit.</p> |
