| 摘要 |
PURPOSE:To simplify the constitution of a device, by connecting a master station and slave stations with a simultaneous transmission/receiving line, and making a slave station respond by a carrier included in a polling signal when the polling signal is transmitted from the master station. CONSTITUTION:The master station 1 codes the number designated to slave stations 2-A-2-nat at a coding circuit 4 by a trigger signal from a trigger signal generating circuit 3, modulates it at a modulator 5 and transmits sequentially a polling signal to each station. The slave station demodulates the polling signal at a demodulator 9, inputs it to an own station selecting signal detecting circuit 10, and when the own station is not selected, the signal is returned as it is to the master station via a driver 11 and a switch 12. When the own station is selected, the monitor information is triggered and inputted to the driver 11 to turn on the switch 12 and the selecting signal of the next station is transmitted to the master station. The signals returend from each slave station are transmitted serially, demodulated 7 and inputted to a comparison circuit 8. A station number code before one station of a polling station number transmitted from a coding circuit 6 is inputted to the circuit 8 and when the both are coincident, it is outputted as monitor information. |
