Automatic/remote RF instrument monitoring system

In an automatic/remote instrument monitoring system of the type having a plurality of RF transponders associated with one of a plurality of parameter sensing instruments remotely located from an interrogate/receiver which transmits an RF activation signal to the transponders and which receives and processes RF transponder signals from the transponders;

• a protocol by which the RF transponder signals are transmitted from the transponders to the interrogate/receiver in response to an activation signal therefrom, comprising:
• providing a preamble field of predetermined preamble data;
• providing an instrument parameter field of instrument parameter data sensed by an instrument;
• providing an instrument identification field of instrument identification data;
• BCH error control coding at least a portion of the fields of data including the preamble field data, instrument parameter field data, and instrument identification field data, and providing an error control code field of BCH error control code data;
• transmission encoding the fields of data;
• simultaneously BCH error control coding and transmission encoding the portion of the fields of data to be error control coded;
• transmission encoding the field of BCH error control code data following the transmission encoding of the portion of the fields of data which were error control coded;
• assembling the transmission encoded fields of data in a predetermined manner to produce a plurality of transponder information packets in which the error control code field follows the instrument identification field, the instrument identification field follows the instrument parameter field, and the instrument parameter field follows the preamble field;
• and
• transmitting the transponder information packets at different frequencies within a predetermined frequency bandwidth as a transponder signal.

In an automatic/remote instrument monitoring system of the type having a pluarlity of RF transponders configured to operate with at least one of a plurality of parameter sensing instruments remotely located from an interrogate/receiver which transmits an RF activation signal to the transponders and which receives and processes RF transponder signals from the transponders, an enable circuit associated with each transponder for causing transponders of the system to initiate transmission of their RF transponder signals at random times with respect to one another in response to the RF activation signal, the enable circuit comprising:

• RF detector means for receiving the RF activation signal from the interrogate/ receiver, detecting the activation signal, and producing a detector signal representative thereof;
• timing means for timing integration periods, wherein the integration periods of the transponders of the system are randomly skewed with respect to each other;
• integrator means operatively coupled to the timing means and the RF detector means for integrating the detector signal over the integration periods and producing an integrator output signal representative of an integral of the detector signal;
• and
• comparator means for comparing the integrator output signal to a threshold value and for producing a transponder enable signal causing the transponder to initiate transmission of its RF transponder signal at random times with respect to other transponders of the system, if the integrator output signal attains the threshold value during an integration period.