| 摘要 |
<p>In a line-test mode, a p-type receiver capable of testing a line can test the status of the signal line connecting, in parallel, a plurality of sensors, transmitters, and termination resistors installed in each monitored area. In a line interface, a first resistor and a second resistor are connected in series between a terminal for applying a direct-current driving voltage and the signal line, and thus the voltage across the second resistor and the signal line is outputted as a diagnosis signal. In the line-test mode, a control unit compares the range of the voltage level of the diagnosis signal with the determination criteria, thereby determining the line status in a monitored area.</p> |
