Title:
火災報知設備
Document Type and Number:
Japanese Patent JP7064890
Kind Code:
B2
Abstract:
[Problem] When a break fault occurs in a loop transmission path and signal transmission is allowed from both sides of the location of the break to continue fire monitoring, a break section is easily found on a receiver side.[Solution] A fire detector 18 is connected to a loop transmission path 12 connected to a receiver 10. When the loop transmission path 12 is normal, a communication connection is made from a transmitting unit 23 to the fire detector 18 to monitor fire. When a break fault occurs in the loop transmission path 12, a break monitoring control unit 28 turns switching circuit units 30a and 30b ON to connect a termination of the loop transmission path 12 to the transmitting unit 23 to make a communication connection from both ends of the loop transmission path 12 to the fire detector 18 to monitor fire. To the loop transmission path 12 a relay 20 including a current direction detecting function with a unique address set thereto is provided, detecting a current normal direction at normal and a current reverse direction at the time of occurrence of a break for transmission to the receiver 10. When a break occurs in the loop transmission path 12, a break section determining unit 32 of the receiver 10 determines, as a break section, a section in which the current normal direction detected by a plurality of said relays 20 is changed to the current reverse direction, and notifies as such.
More Like This:
| JPH0789396 | [Title of Invention] Fire alarm system |
Inventors:
Yoshihiro Matsuda
Kaneko Shigeru
Takehiro Ono
Ishida Ken
Kaneko Shigeru
Takehiro Ono
Ishida Ken
Application Number:
JP2018007889A
Publication Date:
May 11, 2022
Filing Date:
January 22, 2018
Export Citation:
Assignee:
Hochiki Corporation
International Classes:
G08B17/00; G08B17/107; G08B25/04
Domestic Patent References:
| JP6259688A | ||||
| JP8044984A | ||||
| JP8336192A |
Attorney, Agent or Firm:
Takeuchi Susumu