| 摘要 |
PURPOSE:To monitor the state of data transmission of many lines without giving effect onto a communication processing equipment by applying monitoring based on the on/off state of a light receiving element isolated electrically from a light emitting element provided to a transmission/reception data line side. CONSTITUTION:A transmission data from a microprocessor 11 is outputted to a transmission data line 13 via a converting circuit 12 for the interface. In this case, a light emitting diode 18 is lighted when a data of the line 13 represents a space. In approaching a photo transistor (TR) 23 to the light emitting diode 18, the light from the light emitting diode 18 is received and the phototransistor (TR) 23 is turned on. The signal representing the on-state of the phototransistor (TR) 23 is converted into a monitor signal by an interface converting circuit 25 and fed to the monitor. As to the reception data sent from the receiving data line 14, it is monitored similarly.
|
