| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the transmission efficiency of the data serving as the substantial information on a transmission line by polling in sequence the terminal devices which are registered on a table and also inquiring of all terminal devices that are not registered on the table about their registering requests to add them to the table. SOLUTION: A register table is cleared in a register table storage area (S100), and the registering inquiry control data are sent to all terminal devices that are not registered on the register table (S102). A registering request is received from an up channel (S104) and it is decided whether a registering request is given from a terminal device (S106). If the registering request is received from a terminal device (S112), the address of the terminal device is added to the register table (S116). If no registering request is confirmed at all against the registering inquires (S106), the polling processing is carried out to store the data receiving time in the register table (S118). Then the terminal device that is used for a prescribed time is deleted from the register table (S120).</p> |
