| 摘要 |
PURPOSE:To improve the reliability of data in an outdoor unit and an indoor unit and to decrease the possibility of malfunction by discriminating matching of data twice to improve the reliability of the signal data, using the data as true data when they are matched, displaying it as an interface error when a consecutive mismatched time of data reaches a predetermined time so as to stop the communication. CONSTITUTION:When a first interruption by a falling of a signal is received, a level of a reception port is discriminated after the lapse of a time T3 and when the level is a high level, it is discriminated to be production of noise and the procedure is returned till an idle communication line is confirmed. When the level is a low level, a start bit is checked and data are discriminated one after another for each lapse of a time T4 and data by 8-bits are stored. Furthermore, the level of the reception port is discriminated even after the lapse of the time T4 and when the level is a low level, it is discriminated to be production of noise and the procedure is returned till an idle communication line is confirmed. The processing above is repeated, the reception of four characters is made and finally the data are compared with preceding data to make discrimination of data equality twice. When they are equal, the data are used for true data and used for controlling an outdoor unit.
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