| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas meter and a history readout device capable of reading out accurately a cutoff/alarm history even in the changed case so as to read out an elapsed time from a generation time of cutoff or an alarm as the cutoff/alarm history. SOLUTION: A communication control part 15 of this gas meter generates and transmits a first history telegram including the elapsed number of days from the generation time of the cutoff or the alarm as history information, and, after finish of transmission of the first history telegram, generates and transmits a second history telegram including a residual time determined by dividing the elapsed time from the generation time of the cutoff or the alarm by 24 hours. After finish of reception of the first history telegram, a communication control part 25 of this history readout device 2 determines whether the second history telegram is received from the gas meter 1 or not. When the second history telegram is received, the control part 25 displays or records the elapsed time based on the elapsed number of days and the residual time. When the second history telegram is not received, the control part 25 displays or records the elapsed number of days. COPYRIGHT: (C)2004,JPO
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