| 摘要 |
A cellular modem may give notice of changes in modes. The modem will change modes as a result of the breaking of a trip wire or the closing of contacts that are normally open or the opening of contacts that are normally closed or sensing motion or light, or sensing variations in resistance. One contact is provided to wake the unit from "sleep" and the other is provided to detect intrusion, motion, etc. Light detectors can detect light, such as when a closed container is opened. Closed contacts can be used in parallel to change any mode or open/closed contacts in parallel/series. The modem can be used to apprehend people breaking into or stealing luggage, equipment, boxes, etc. The present invention informs the user when the object being monitored is being moved or opened and can track the object's location. |
