| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To specify a communications apparatus in which a fault has occurred, and further, to disconnect the faulty communication apparatus from a network. <P>SOLUTION: A communications apparatus in a communication system, where communication is performed with each other via a two-wire type communication line with termination resistors being connected to both ends, comprises: a resistor which is connected, in parallel with branch lines connected with the two-wire communication line, respectively, and of which the other terminal is connected with a ground; and an abnormality deciding means for deciding whether bus in the present communication apparatus is abnormal, based on a differential voltage on the branch line. when a differential voltage which is decided as being dominant is received as many as or more than predetermined times that the bus is decided as being abnormal, the abnormality determining means determines the bus in the present communications apparatus as being abnormal. Furthermore, the termination resistor comprises a first resistor and a second resistor, connected in series with the first resistor and the communication system, comprises a termination circuit which is constituted of first and second resistors and a capacitor which is connected between the first resistor and the second resistor, and of which the other terminal is grounded. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
