| 摘要 |
PURPOSE:To prevent a malfunction, by treating a binary signal in a ternary coded state and therefore preventing the transmission of signals to a receiving device in a fixed logic value state. CONSTITUTION:When logic value 1 is applied to an input part 5 of a converting circuit 4 within a transmitting device 1, a signal of a waveform (a) emerges at an output part 6 and is then transmitted to the secondary side of a transformer 8 of a deciding device 2 via an amplifier 7 and a cable 3. This signal is rectified and smoothed to be applied to relays A-D. Thus all contacts of a contact circuit 13 are turned on, and logic value 1 is transmitted. When a logic value O is applied to the part 5, a signal of a waveform (b) emerges at the part 6. Then all contacts of a contact circuit 14 are turned on, and logic value O is delivered. If the amplifier 7 has a fault, no output is obtained at the circuit 13 nor 14. In case the circuit 4 has a fault, the transformer 8 has similar waveforms. And no output is obtained at the circuits 13 and 14. |
