Device and Method for Anticipating Failure in a Solenoid Pilot Operated Control Valve for a Fieldbus Manifold Assembly

A method of detecting degradation of a coil in a solenoid pilot in a fieldbus control valve system, said method characterized by:

• providing a power circuit with a direct current power source that powers said solenoid coil;
• providing a driver that communicates said power source to ground to close and open the power circuit;
• providing a resistive element in series with said direct current power source, said driver and said solenoid coil;
• generating a frequency pulse train to said driver having a characteristic so as not to affect actuation of said solenoid coil;
• measuring an initial voltage level during said frequency pulse trains between said solenoid coil and said resistive element;
• storing said initial voltage level in a memory device;
• measuring a subsequent voltage level during a subsequent frequency pulse train;
• comparing said subsequent voltage level to said initial voltage level;
• and providing an indicator warning when said subsequent voltage level has changed a predetermined amount from said initial voltage level.