INTERFACE CONTROL SYSTEM OF CIPHER DEVICE

摘要

PURPOSE:To ensure normal operation from the end of the reception data to the end of decoding action by transmitting a coded signal from the transmission side in response to the OFF of a control signal and completing the decoding action at the reception side by the OFF of a carrier detecting signal. CONSTITUTION:The transmission data SD and ''1'' sent from a HOST are supplied to a selector circuit 11 and the selected in accordance with the control signal fed from a delay part 12. The part 12 produces a control signal to select ''1'' when the RS signal fed from the HOST is off. Then ''all-1'' is supplied to a data coding processing part 13, and the coding data is transmitted. A carrier is detected at the reception side, and the CD signal is produced. A decoding processing part 21 decodes the data while the CD signal is kept on and supplies it to a selector 24 via a delay part 22. Then ''1'' is outputted in the form of the reception data RD in the period between the carrier is turned off and the part 21 stops its working by the OFF of the CD signal.