Methods for consolidating module types for industrial control systems

A programmable discrete input module comprising:

• a voltage converter configured to convert an alternating current input signal to a direct current input signal;
• a pulse width modulation module configured to generate a pulse width modulated signal based upon the direct current input signal;
• a pulse width demodulation module, the pulse width demodulation module configured to generate a demodulated pulse width signal;
• an isolator configured to isolate the pulse width modulation module and the pulse width demodulation module, the isolator configured to generate an isolated pulse width modulated signal based upon the a pulse width modulated signal for the pulse width demodulation module to generate the demodulated pulse width signal;
• a first comparator communicatively coupled to the pulse width demodulation module, the first comparator configured to compare the demodulated pulse width signal with a first programmable reference, the first comparator configured to output a first comparator output signal based upon the comparison;
• a second comparator communicatively coupled to the pulse width demodulation module, the second comparator configured to compare the demodulated pulse width signal with a second programmable reference, the second comparator configured to output a second comparator output signal based upon the comparison;
• and
• a digital filter communicatively coupled to the first comparator and the second comparator, the digital filter configured to digitally filter at least one of the first comparator output signal or the second comparator output signal to generate a discrete input signal.

A method for generating a discrete input signal, the method comprising:

• receiving an input signal;
• generating a pulse width modulated signal based upon the input signal at a pulse width modulation module;
• generating an isolated pulse width modulated signal based upon the pulse width modulated signal at an isolator for demodulation by a pulse width demodulation module, the isolator configured to isolate the pulse width modulation module and the pulse width demodulation module;
• generating a demodulated pulse width signal at the pulse width demodulation module based upon the isolated pulse width modulated signal;
• generating a first comparison signal based upon a comparison of the pulse width demodulation signal and a first programmable reference at a first comparator;
• generating a second comparison signal based upon a comparison of the pulse width demodulation signal and a second programmable reference at a second comparator, the first programmable reference different from the second programmable reference;
• and
• filtering at least one of the first comparison signal or the second comparison signal at a digital filter to generate a discrete input signal.