Duplex bi-directional multi-mode remote instrument reading and telemetry system

A data collection system, comprising an interrogation apparatus and at least one instrument link, interconnected to a data gathering device located remote from said interrogation apparatus, said interrogation apparatus further including:

• an interrogation transmitter means for transmitting a radio frequency (RF) signal at a predetermined frequency to said at least one instrument link;
• an interrogation receiver means for receiving an informational message from said instrument link, said interrogation receiver means being tunable to any of a number of center frequencies which lie in a prespecified bandpass;
• frequency determining means, using said interrogation receiver means, for determining what center frequency, in the prespecified bandpass that an informational message from said instrument link should be transmitted on;
• interrogation signal determining means, responsive to said frequency determining means, for determining content of an interrogation message, said message to be transmitted by said interrogation transmitter means, wherein the interrogation message provides at least the center frequency for transmitting the informational message;
• tuning means for tuning said interrogation receiver means to the center frequency determined by said frequency determining means so that informational messages from said instrument link can be received;
• and
• informational message signal processing means, responsive to said interrogation receiver, for both processing the informational message received and providing an output representative of transmitted information;
• and
• wherein each said instrument link further includes:
• an instrument link receiver tuned to the predetermined frequency of the interrogation transmitter, said instrument link receiver providing an output representative of a transmitted interrogation message;
• interrogation signal processing means, responsive to said instrument link receiver, for processing the receiver output to determine at least what information is to be transmitted by each said instrument link and at what center frequency to transmit the informational message;
• instrument link transmission means for transmitting the informational message at the center frequency determined by said interrogation signal processing means, where said instrument link transmission means is tunable to any of the center frequencies that lie in the prespecified bandpass;
• and
• informational message generating means, responsive to said interrogation signal processing means, for generating the informational message for transmission by said instrument link transmission means, wherein the informational message generated provides the information requested in the interrogation message.