| 摘要 |
<p>An alarm system includes a plurality of sensors (1, 10, 11), each of which is adapted to deliver signals and actuate logic B so as to activate an alarm (9) either directly or through the medium of a time delay circuit (7). At least one of the sensors has the form of an activating unit (1) that includes an indicator (4) whichis adapted to show several different signal pictures (21-25). The logic (8) is adapted to cause the activating units to show a first signal picture (21) when the system is in a normal state (30). When activated, each sensor delivers to the logic a first activating signal (31), wherein the logic causes a corresponding second signal picture (22) to be shown on the indicators of all activating units (21), and wherein the logic causes the alarm (9) to be triggered through the medium of a time circuit (7) subsequent to the expiration of a time period set in the time circuit. Upon receipt of a second activating signal (32) within the time period running from the time of the first activating signal (31), the logic (8) causes the indicator (4) of each unit to show a corresponding third signal picture (23). Subsequent to a third activating signal (33) received within the time period, the logic (8) resets all logics to the normal state (30), wherewith each unit (1) is caused to show the first signal picture (21) on its indicator (4) and the logic (8) causes an alarm (9) to be triggered upon receipt of a fourth signal (34) within the time period set by the time circuit (7).</p> |
