| 摘要 |
PROBLEM TO BE SOLVED: To provide a sensor network that can enhance added value.SOLUTION: A sensor network 1 comprises a device 3 supplied with power from a system power source 2, and a plurality of sensor devices 4 each of which operates with a battery 40 as a power source. The device 3 has a first communication part 32. Each of the plurality of sensor devices 4 includes a sensor unit 41, a light emitting unit 43, a second communication unit 42, a light emitting unit 43 and a second control unit 44. The second control unit 44 is configured to make a radio signal containing communication check information be periodically transmitted from the second communication unit 42 to the first communication unit 32, and determine the presence or absence of establishment of communication on the basis of whether the second communication part 42 receives a radio signal containing replay information from the first communication part 32. Each of the plurality of sensor devices 4 is configured to emit light from the light emission part 43 of respective sensor devices 4 when the absence of communication establishment is determined at the second controllers 44 of at least two sensor devices 4 out of the plural sensor devices 4.SELECTED DRAWING: Figure 1 |
