| 摘要 |
PURPOSE:To easily monitor the line by the receiving side as to whether there is a fault or not, by inserting a pulse of narrow width by the reverse polarity when the same code of an asynchronous data has continued exceeding the prescribed length, in the system for transmitting a binary asynchronous data. CONSTITUTION:When the same code of an asynchronous data (a) provided to the input terminal 1 of the transmission side has continued exceeding T1, a refresh pulse of pulse width T0 which is narrower than the minimum width T of the asynchronous data is inserted by the reverse polarity. The receiving side executes decoding by disregarding the refresh pulse having relation of T>>T0, and makes it a regenerated receiving code (c). At the normal time, the refresh pulse of the reverse polarity is inserted at every T1 of the same code, and therefore, it becomes easy to monitor the line by the receiving side as to whether it is a fault or not. Moreover, since not only the transmission becomes easy due to decrease of the DC component but also the refresh pulse is inserted even if the original code continues ''0'', the AGC can be operated by detecting the level. |
