Abstract: Information in the form of redundant message packets is sent between a remote device and a host device, e.g., a wireless security system. In order to conserve energy, the frequency of trigger events in the remote device is determined, and the number of redundant message packets sent is based on the determined frequency.

Abstract: An apparatus and method for sending messages from a sensor to a system controller in a wireless security or monitoring system, including processing signals from the sensor and generating message packets which include information derived from the sensor signals.

Abstract: A security system sensor has a lens lying in a forward plane that focuses received energy to a focal point that is internal to the sensor. A sensing element is located at or near the focal point of the lens. A funnel-shaped chamber between the lens and the focal point is substantially vacant so that received energy is received by the sensing element. A battery housing is positioned so that the physical volume of a battery power source contained therein is mainly rearward of the lens and the vacant funnel-shaped chamber, yet forward of a plane that is immediately rearward of the sensing element. Also, a dividing barrier, interposed between the chamber and the battery power source, extends to and seals with the sensing element and the lens, thereby providing a seal for the vacant, funnel-shaped chamber.

Abstract: A transformer system couples a control panel with a power line to support two-way communications over the power line. A first transformer steps-down the power line voltage, supplying power to the control panel. A second transformer and associated capacitors provide a low impedance path at the communication signal frequencies and a high impedance path at the power frequency.

Abstract: In a security or monitoring system having a system roller and one or more sensor/transmitters, information is sent from the transmitter to the system controller in message packets. As improved message packet protocol provides a front porch pulse, a set of synchronization bits, a start bit, a set of information bits, a first stop bit, a set of error detection bits, and a second stop bit.

Abstract: A security alarm system including multiple, zone distributed audio monitors and alarm sensors which report and verify detected alarms and communicate with a system controller and central station. Ambient audio is continuously and selectively recorded in a storage memory and is replayable to verify alarms detected at the alarm sensors. During pre-alarm conditions, all audio inputs are summed and recorded. During an alarm state, the audio input of the audio monitor physically closest to a reporting alarm sensor is automatically selected and the post-alarm audio activity is recorded only for that sensor. The central station is able to selectively communicate via a phone link with each audio controller and engage in half duplexed voice communication with the alarm site, remotely playback and listen to the locally recorded audio data, or program each audio controller. The monitored audio data is stored in RAM storage in discreet segments corresponding to predetermined periods of pre-alarm and post-alarm data.

Abstract: In a battery-powered sensor such as a smoke detector, a passive report of unacceptable battery condition is first given while an active report of such condition is inhibited. Then, after the lapse of a period of time after the unacceptable battery condition is first detected, the active report is given.

Abstract: In a security system having a remote monitoring station, a sensor is tested when the security system is in a normal operating mode. The sensor is tested by actuation of a button on the sensor. Actuation of the button generates a signal indicating that a test has been conducted. Upon the generatation of both an alarm signal generated by the test and a signal indicating that a test has been conducted, the security system determines that the alarm signal was generated by a test of the sensor and not by the detection of alarm conditions by the sensor.

Abstract: An improved short distance, battery powered, amplitude modulated RF transmitter for transmitting encoded security data. An oscillator stage provides a control crystal and filter which are feedback coupled between the emitter and base of a transistor to oscillate at the fifth overtone of the fundamental crystal frequency. A filter tuned to the third harmonic of the overtone frequency selects the carrier frequency which is coupled via a resistive attenuator to an amplifier/filter stage, before the carrier is amplitude modulated with encoded security data. The improved transmitter circuit compensates for crystals exhibiting variations in series resistance and provides increased output power and improved frequency stability to temperature and over time. A foil antenna stage is augmented with the plates of the battery power supply to further improve performance.

Abstract: An active, relatively high gain, low power consuming band pass filter circuit centered at approximately 6 KHZ and having a pass band of 100-200 HZ. In a disclosed glass breakage sensor, the filter couples sensed ambient sounds of breaking glass to associated detection, driver and annunciator means. Signals of appropriate duration and frequencies indicative of breaking glass are thereby monitorable to define and induce an alarm condition within a security system.

Abstract: A security alarm network including a plurality of microprocessor-based, subscriber system controllers, wherein each controller is capable of responding to a plurality of distributed wireless and hardwired sensors/transducers and is programmable via user, central station and installer-entered system and network parameters.

Abstract: A time multiplexed integrated alarm contact for reporting detected alarm conditions to a system controller in a hardwired alarm system and wherein distinguishable binary frequencies are used for synchronizing/responding and for programming the contact. During programming, an identity code is written into an included shift register and non-volatile memory defining the system reporting interval and the contact's reporting interval within the system interval. Controller initiated synchronizing signals induce each contact's status transmission with or without resetting an alarm buffer and whereby redundant alarm reports may be obtained.

Abstract: A method and apparatus in a security system whereby a central processing unit self learns the identities of its distributed wireless keypad and alarm transmitters. Each transmitter includes an electrically eraseable memory containing signal conditioning data and a pseudo randomly programmed identification code. During a transmitter initiating programming condition, the CPU captures the received identification code of each transmitter and establishes an identity code table by which subsequently received transmissions are confirmed as belonging to the system.

Abstract: A multiplexing method for an alarm system is disclosed in which a plurality of transponders connected in parallel by a pair of wires each monitors an opening and responds to a synchronizing signal after a preprogrammed time delay corresponding to the particular transponder if the opening it is monitoring is secured.

Abstract: A family of serially programmable integrated circuit transmitters for use in various sensor and user data input transmitters of a short-range radio frequency linked security system. Each transmitter transmits two bits of data for each data frame of a pulse position encoded message format with multiples of each message being transmitted with each transmission, the number of messages depending upon the type of message. Each user data input transmitter includes means for decoding keyboard entered data, re-circulating means for storing the user entered data and programmed system parameters and means for time partitioning intra and inter-message transmissions. Each sensor transmitter includes means for storing uniquely programmed system preconditioning parameters, means for sensing and verifying alarm conditions and means for time partitioning intra and inter-message transmissions.