Method and apparatus for auto-calibration of signal conditioning electronics

摘要

Numerous signal conditioning circuits on a plurality of printed circuit boards are calibrated remotely by a signal processing unit which sends coded signals to each board, either sequentially or in parallel, to connect either on-board or off-board test signals to one of the conditioning circuits in place of its field generated input. The processing unit utilizes the actual and expected responses of each conditioning circuit to low and high test signals to generate a gain and an offset which are applied to the conditioned field signal to provide a calibrated signal. The time constant for each conditioning circuit is also measured periodically, or upon a selected temperature change, for use in generating a minimum waiting period for obtaining valid data following transfers between the field generated signals and the test signals.