| 摘要 |
PURPOSE:To supervise an error rate with a simple equipment by generating the violation of code rules in a monitor signal sent through a monitor line when any transmission error is detected in a transmission line. CONSTITUTION:A coded transmission signal from a transmission terminal station 2 is sent through a transmission line 5 and a repeater 4 to a reception terminal station 3. A monitor transmission terminal station 12 sends a coded transmission code as a monitor signal X. When an error monitor circuit 6 connected to the repeater 4 detects the violation of the code rules of a transmission signal, an output pulse Y is generated. A monitor repeater 14 relays a monitor signal X and when the output signal Y exists, the repeater 14 generates the violation of the code rules (e.g., the inversion of an optional bit) in the monitor signal X and sends the result. A monitor reception terminal station 13 detects the violation of the code rules of the monitor signal to detects the error in the transmission line 5. Then a simple circuit is enough for the repeater 14 and an idle line of the transmission lines 5 is used for the monitor line.
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