| 摘要 |
<p>An arrangement for use in a safety notification system includes a source of negative voltage, a first resistor arrangement, and a circuit arrangement. The first resistor arrangement is coupled between the source of negative voltage and the signal output of the safety notification system. The circuit arrangement is configured to detect a first voltage at the signal output of the safety notification system, and to generate a trouble signal output if the first voltage at the signal output is above a first threshold or below a second threshold.</p> |
