| 摘要 |
PURPOSE:To improve the utilizing efficiency of a transmission line with simple processing by providing an interruption output circuit and an interruption detection circuit to a transmission line so as to start reconstitution only when the reconstitution at the circuit network system is required. CONSTITUTION:A data is discriminated by a data judging level 13 of a reception circuit for the level of the transmission line 1 and when the frame is addressed to the own node, a data is fetched to a reception data memory 7. When it is judged that the frame is a token frame representing the right of transmission, a CPU9 stores it to a control memory 10 temporarily that the CPU has the token to output a transmission data in a transmission data memory 8 from a transmission circuit 5 to the transmission line 1 and it is finished, a token frame is generated and fed to the next node so as to erase temporarily the storage of the token in the memory 10 temporarily. Further, an interruption level detection circuit 3 informs always the state of the transmission line 1 to the CPU9 depending on the discriminating level 15 and goes to a tentative master when an interruption is detected while the own node has the right of transmission, the circuit 3 goes to a tentative master to attain reconstitution. |
