| 摘要 |
PURPOSE:To control the transmission so that the unidirectional transmission from the central unit to terminal can smoothly be made, by unconsciousness of the central unit for the processing state at the terminal, in the ON-line system treating inquiry and answer as the base. CONSTITUTION:The unidirectional transmission data(information outputted unidirectionally) is received at the special buffer 201 to tell it to the operator. FF206 is set with the instruction of unidirectional transmission, and is reset with the release instruction or the end of transmission to recognize various chocking states, and FF207 is set at the end of inquiry and answer and is reset with the instructions other than the end, to recorgnize the time point of the final instruction reception end of inquiry and answer. The logical sum between those outputs and the output of the buffer free detection circuit 219 is fed to the circuit 212 after inversion to inhibit the required input. The logical sum output 209 is inputted to the AND circuits 210, 211 to produce the unidirectional transmission permission, i.e., choking permission SNOD signal for transmission 205. The choking state of emergency or normal is released through the reset of FF206 with the choking release or unidirectional transmission end signal via the decoder 204. |
