Diagnostic for pulsed solenoid i/p functionality

A system for diagnosing failures in a digital solenoid I/P converter in a process control system, the system comprising:

• a digital solenoid I/P converter, including an I/P coil and drive circuitry, the digital solenoid I/P converter being configured to cause an armature to move from an off-position to an on-position when actuated;
• a controller configured to cause a fixed voltage to be applied to the I/P coil at a first time;
• a current sensor configured to sense an amount of current associated with the I/P coil;
• a timer configured to determine an amount of time elapsed from the first time;
• and
• a diagnostic circuit configured to:
• perform a first comparison of the sensed amount of current associated with the I/P coil and a maximum desired current level;
• cause, based on the first comparison, a digital logic line to trip when the sensed amount of current associated with the I/P coil reaches the maximum desired current level;
• receive, from the timer, an indication of an amount of time that has elapsed from the first time to a second time associated with the tripping of the digital logic line;
• perform a second comparison of the (i) the amount of time elapsed from first time to the second time to (ii) an expected amount of elapsed time from the application of the fixed voltage to the I/P coil after which a digital logic line trip will occur for a properly functioning I/P coil and drive circuitry;
• and
• determine, based on the second comparison, whether the I/P coil and drive circuitry are properly functioning or whether one or more of the I/P coil or the drive circuitry has failed.