| 摘要 |
PURPOSE:To shorten a poling period sharply by poling a terminal equipment in each group, and only when a response indicating the existence of transmission data is sent from a terminal of the group, poling the inside of the group individually. CONSTITUTION:A broadcasting center 100 is connected with terminal equipment 500 through a transmission line 400. The broadcasting center 100 is formed by a center CPU110, a source group 120 of a video voice information, a video voice switching device 130, a head end 140, and MODEMs 111, 112. The center CPU110 executes poling to the terminal equipment 500 on the basis of a group address, and only when it is necessary to inform response data to the CPU110, the response data are sent within a prescribed time. If the response data are not sent within the prescribed time, the CPU110 executes the poling of the succeeding group. If response data are sent from a plurality of terminal equipment 500, respective equipment is individually poled on the basis of inherent address to check individual response data. |
