LINE ERROR MAIN CAUSE COLOR-CODING DISPLAY CIRCUIT

摘要

PURPOSE: To easily discriminate the main cause of a line error by constituting a multicolor light emitting LED so as to emit light in a predetermined color among multiple emittable colors corresponding to the main cause of the line error. ;CONSTITUTION: By using the multicolor LED 7, when a circuit is normal, since CD signals 3 outputted from a modem device 2 output an 'L' level, the (a) of the light emitting LED 7 is lighted through a buffer 6. Since the level of SQD signals 4 becomes the 'L' level at the time of SQD abnormality, since the (b) of the LED 7 is lighted through the butter 6, the color of the LED 7 which was normal is changed and the generation of the SQD abnormality is detected from an outside. Also, when carrier signals are turned OFF, since the level of the CD signals 3 becomes 'H,' the light emission of the LED 7 is changed. Thus, the main cause of the line error is discriminated by one LED. Further, for errors in a cyclic redundancy check CRC, two sets of the output of the I/O of a line control part 8 are provided and the error is discriminated.;COPYRIGHT: (C)1996,JPO