| 摘要 |
PURPOSE:To prevent erroneous transmission and to improve the operability by providing a means discriminating a missing of at least one field in the frame reproduction mode and a means inhibiting the communication in response to the discrimination. CONSTITUTION:The state of a transmission switch 7 is discriminated not in the transmission state while the state of a flag representing the transmission state is observed in the transmission routine and a timer OFFTIM turning off the power supply automatically is preset when the switch is depressed. Then the presence of a reproduction envelope of the 1st field is discriminated by the detection of the output of an envelope detection circuit 22, and when the output exists, whether or not the frame reproduction mode exists is discriminated by the reproduction mode switch 16. As a result, in case of the frame reproduction mode, the reproduction envelope of the 2nd field is checked and when no reproduction envelope exists, the transmission is inhibited. That is, in case of the frame reproduction mode, at least one field is missing, then the transmission is inhibited to prevent erroneous transmission thereby improving the operability. |
