| 摘要 |
<p>Elevator components (310, 320) can communicate with each other over a signal path (330) using a combination of direct current (DC) and oscillating signals. An oscillating signal on the signal path (330) can be interpreted as indicating a first state of a component (320) (e.g., "active"), a first DC signal on the signal path (330) can be interpreted as indicating a second state of the component (e.g., "inactive") (320), and a second DC signal on the signal path (330) can be interpreted as indicating a third state of the component (e.g., "fault") (320). Thus, three states of the component (320) can be communicated over a single signal path (330).</p> |
