| 摘要 |
PURPOSE:To realize the control for a number of load machine boards with a small number of control lines by using the aural frequency signals different according to the load machine boards for the signals which control a number of load machine boards via the supervisory board. CONSTITUTION:The operation and nonoperation command signals given from start- stop unit 1 of supervisory board A are converted into the aural frequency signals corresponding to transmission unit 2 via unit 2 corresponding to the load machine board and then sent to reception unit 2' of site control board B storing the load machine board via amplifier 5. One of units 2' containing the tuning fork filter answers to the aural frequency signals to control corresponding relay Ry. Control board B transmits the answer signals and fault signals in the opposite direction to the above via transmission units 3 and 4 plus reception units 3' and 4' each to light up pilot lamps E and E' as well as to sound buzzer G. As a result, a number of load machine boards can be controlled with three pieces of control lines. |
