Proximity sensing system with component compatibility testing

A proximity sensing system, comprising:

• a proximity probe configured to generate an oscillating magnetic field in response to receipt of an oscillating current via a cable, the proximity probe and the cable forming a resonant circuit possessing a capacitance C1 in parallel with an inductance L1, wherein the resonant circuit possesses an impedance Z1 that is a function of C1 and L1;
• a controller in electrical communication with the resonant circuit via the cable and configured to output an initial proximity signal based upon a measured change in the impedance Z1 resulting from perturbation of the generated magnetic field by a ferromagnetic target positioned at a test position with respect to the proximity probe;
• and
• a self-testing subsystem configured to,
• receive the initial proximity signal,
• place a predetermined self-testing impedance Z2 in parallel with the resonant circuit,
• receive a modified proximity signal, different than the initial proximity signal, output by the controller in response to placement of the self-testing impedance Z2 in parallel with the resonant circuit and placement of the ferromagnetic target at the test position,
• receive a reference proximity signal representing the modified proximity signal output by the controller in communication with a predetermined cable and a predetermined proximity probe with the target positioned at the test position,
• determine a difference between the reference proximity signal and the modified proximity signal;
• and
• output an incompatibility signal after measuring the difference to be greater than or equal to a threshold amount.