| 摘要 |
PURPOSE:To make it possible to very easily execute the control for the loop test, by detecting a position where a transmission error has occurred, making certain of the response whenever one character is transmitted. CONSTITUTION:The sychronous state of a data of the transmitter/receiver circuit 2 is changed to the start-stop synchrnous system from the synchronous system only in case of the circuit loop test, by the command C1 from the control part 3. And the circuit 2 can transmit and receive a data by the start-stop synchronous system by using a clock of the frequency dividing ratio 1/1 of the circuits L1, L2, which is received from the synchronous MODEM1, and the synchronous system is changed to the start-stop system at the time of the loop test. In this way, the control for the loop test can be executed very easily by detecting a position where a transmission error has occurred, making certain of the response whenever one character is transmitted. |
