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.

Abstract: An automatic/remote instrument monitoring system and method are disclosed. RF transponder units are operatively connected to and monitor one or more parameters of a remotely located instrument. The transponders include RF receivers that sample received RF signals at a low duty cycle and look for a common wake-up signal transmitted from a mobile data collection unit. All transponders receiving the common wake-up signal simultaneously energize their respective transmitters and transmit their respective messages over a predetermined RF transmission bandwidth to receivers in the mobile unit. The time and frequency parameters of the transponder transmissions are varied in a manner such that the transmission signals of simultaneously transmitting transponders differ. A plurality of RF receivers in the mobile unit are respectively tuned to collectively receive the transponder transmissions, across the entire transmission bandwidth.