| 摘要 |
PURPOSE: A method for duplexing a demodulator in a digital TV repeater is provided to perform a duplex switching automatically by sensing a mal-operation of a demodulator. CONSTITUTION: A central controller of a digital TV transmitter resets a synchronizing error counter of a demodulator and initializes a timer for counting a synchronizing error generated during a specific time if a power source is applied(S400). The central controller monitors an operation state of the demodulator periodically and checks whether an error is generated in a power source of the demodulator(S401). If an error is generated, it is checked whether an auxiliary demodulator for a duplexing is normally operated(S409). If the auxiliary demodulator is normally operated, a duplex switching is performed using the auxiliary demodulator(S408). If the auxiliary demodulator is not operated, an alarm is generated to a remote control unit by wireless(S406). If the demodulator is normally operated, it is checked whether the demodulator is normally operated(S402). If the power source of the demodulator is not normally operated, the above (S409), (S408) and (S406) processes are performed. If the demodulator is normally operated, it is checked whether an error with respect to a synchronizing signal detecting is generated(S403). If an error is generated, the synchronizing error counter is increased by one(S404). It is checked whether the number of the synchronizing error counter exceeds to a set critical value(S405). If the number of the synchronizing error counter exceeds to a set critical value, an alarm is generated to the remote control unit(S406). The remote control unit commands to the control unit for switching an operation of the demodulator into the auxiliary demodulator(S408). It is checked whether the number of the synchronizing error counter exceeds to a set critical value based on a completion of a synchronizing error timer(S410).
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