| 摘要 |
PURPOSE:To inform securely the transmission abnormality of a control signal of an operator by providing a transmission abnormality signaling means which acts when the repetitive transmission of control signal is stopped, on a centralized control panel. CONSTITUTION:In terms of a centralized control panel 1, the reception of a transmission signal by a terminal 2 is recognized by receiving an answer-back signal. When a transmission recognition signal is not returned back from the terminal 2 in spite of the reception of control signal from the control panel 1, said panel 1 transmits repetitively the same control signal by a repetitive transmission means by prescribed number of times (for instance, 16 times). However, when an action recognition signal is not returned back from the terminal 2, it is considered that transmission abnormality occurs, and a green action display lamp L2 is caused to blink, thereby displaying the transmission abnormality. Furthermore, a buzzer also signals that the transmission abnormality occurs. |
