CONTROL METHOD FOR MASTERLESS SERIAL BUS OCCUPATION

摘要

PURPOSE:To attain the control of the occupation of a serial bus free from collision of data on a bus by obtaining an optimum transmission queuing time from a transmission PC number in a transmission data format, a transmission time interval set by a setting device, and the amount of transmission data in the transmission data format to set it in the counting devices of the respective PCs. CONSTITUTION:An MPU 24 reads the self-PC number, the transmission interval, and the total PC number set in the setting device 27, and stores them in a memory 26. Then the MPU 24 sets the maximum queuing time in a counting device 25 and comes to a bus monitoring state in order to confirm that there is another PC on the serial bus currently being transmitted. In case there is no PC to be data-transmitted on the serial bus, the device 25 supplies to the MPU 24 a transmission timing after the lapsing of the maximum queuing time, and the MPU 24 executes the transmission. After ending the transmission, the MPU 24 gets again the maximum queuing time in the device 25, and executes the arithmetic and control operation. The above described operation is repeated thereafter.