| 摘要 |
PURPOSE:To transmit assuredly the oil supply information without using a special wiring by transmitting the oil supply information via a distribution line and at the same time using a round-in preventing means to prevent the round-in of signals in a signal transmission mode. CONSTITUTION:The oil supply information is transmitted via a wiring between an oil supply device consisting of an oil supplier 2-1 and an oil supply information transmitter 3-1 and an oil supply data processor POS20. A modulator 27 modulates the series data delivered from a transmission/reception circuit 37 via an AND circuit 45 and supplies the obtained modulation signal to a coupling circuit 29. The circuit 29 transmits the modulation signal to a distribution line 30. While the circuit 37 transfers the data given from the POS20 to a transmission/ reception circuit 36. A round-in preventing means 40 consisting of a transmission signal detecting circuit 42, a reception signal detecting circuit 43 and AND circuits 44, 45 is provided to prevent the round-in of signals between the modulator 27 and a demodulator 28. |
