| 摘要 |
PURPOSE:To reduce the number of signal lines and detect disconnections by cross-wiring plural air conditioners in parallel with a control device to connect them with two signal lines and connecting terminals of these signal lines to the control device. CONSTITUTION:A transistor TR38 is made non-conductive by the signal supplied to a signal transmission/reception switching input terminal 54 which is provided in an instruction signal transmitting/receiving part 1 in the control device side, and the transmission mode is set when a TR36 is made conductive. The signal supplied to a transmission signal input terminal 55 not only is flowed to the control device side through a signal transmission line 3, a light emitting element 62 in the first operation signal transmitting and receiving part 2 in the air conditioner side, and a signal transmission line 4 but also drives the second operation signal transmitting and receiving part 32 to check it. If the TR38 is made conductive and the TR36 is made non-conductive, the reception mode is set, and the signal from the first operation signal transmitting and receiving part 2 is received by an instruction signal transmitting and receiving part 1 through the loop passing the signal transmission line 4, a light emitting element 67, and the signal transmission line 3. |
