| 摘要 |
<p>In a communication apparatus comprising a communication path through which a message passes and, a plurality of communication subjects, each of which includes a message transmission function to the communication path, and a read function for reading the message from the communication path, each communication subject maintains a communication cumulative amount table for each communication subject so as to store the communication cumulative amount of messages transmitted by each communication subject as communication history data; the communication subject adds the latest communication cumulative amount in the communication cumulative amount table to a message which is transmitted to the communication path; the communication subject compares the communication cumulative amount table stored thereby with the communication cumulative amount added to the message being received. Thus, troubles of the communication subjects in the communication apparatus according to the result of the comparison can be detected. In addition, without complicated operations of each communication subject, while the overhead of processes is kept low, it is possible to prevent a bad effect due to a trouble or error of communication subjects from being propagated to other communication subjects.</p> |
