| 摘要 |
<p>Scanning Control System A scanning control system is disclosed for remotely sensing or monitoring a predetermined condition or state, such as the presence of a fire, by means of one or a multiplicity of detecting stations at one or a multiplicity of locations with each detecting station providing a positive indication of the location of each predetermined condition sensed. A scanning or control panel is electrically connected with the detecting stations by means of four wires extending from the panel regardless of the number of detecting stations utilized in the system. Two of the four wires are power and return leads from the scanning panel to all of the detecting stations, a third wire provides an interrogation pulse with the first detecting station receiving an interrogation pulse from the scanning panel and each succeeding detector station receiving an interrogation pulse generated by the preceding detector station at a predetermined later time following receipt of the interrogation pulse from the preceding detector station, and the fourth wire carries a pulse train of timewise spaced data pulses genera-ted by the detecting stations in response to receipt of an interrogation pulse. Each data pulse generated by each detecting station is controlled as to pulse width so as to be indicative of the presence or absence of the condition being monitored, such as the presence or absence of a fire. The data pulses are processed at the scanning panel and an alarm generated if the pulses are indicative of a sensed condition such as a fire. Provision is also made for visually indicating the location or locations of all sensed conditions causing the alarm.</p> |
