| 摘要 |
PURPOSE:To allow a simple device to decide priority and to prevent data collision between plural stations, by allowing each image processor to transmit its station data when receiving a packet from a specific station which serves as a temporary master station during system actuation. CONSTITUTION:When terminals A, B, C, and D are powered up, the terminal A serves as a temporary master station firstly to issue a command empty packet. This command empty packet is transmitted through a transmission line 1 to the terminal D, which once knowing the said packet is empty, writes abit for showing that the loop is being connected, its station address (D), and the address of a transmission destination in the packet and then sends it to the terminal C when a transmission request is given. Further, said packet is transmitted to the terminals B and A successively and if the address of some terminal coincides with said transmission denstination address, the packet is fetched to return an answer signal to the transmitting origin terminal D. When the terminal D has no transmission request, the empty command packet is transferred to the trailing terminal C. |
