| 摘要 |
PROBLEM TO BE SOLVED: To prevent development to a serious accident and secure safety even when a communication abnormality occurs in a communication line transmitting shutoff request. SOLUTION: A shutoff valve unit 20 transmits a communication confirmation signal to an operation device 10 via the communication line 3 by a communication confirmation signal transmitting means 23a. When receiving the communication confirmation signal via the communication line 3 by a communication confirmation signal means 13a, the operation device 10 transmits a response signal to the shutoff valve unit 20 via the communication line 3 by a response signal transmitting means 13b. When the shutoff valve unit 20 does not receive the response signal corresponding to the transmission of the communication confirmation signal by a response signal receiving means 23b, the shutoff valve unit 20 determines that a communication abnormality occurs by a communication abnormality determination means 21a1, and shuts off the shutoff valve 26 by controlling a drive means 27 by a shutoff control means 21a2. COPYRIGHT: (C)2010,JPO&INPIT
|
