Abstract: A piezoelectric resilient arm contacts a projected object and establishes a reference relative to sensitivity means and differential detector means including feedback coupled amplifier means which operates in cooperation with a balanced square wave generator means for producing a switched output upon detecting motion. An alarm signal is produced which has a duration related to the rate of change of movement of the piezoelectric resilient arm. Programmable delay means appropriately enables an annunciator and/or wireless communication link to a system controller.

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.