A programmable discrete input module is described. In one or more implementations, the programmable discrete input module comprises a pulse width modulation module configured to generate a pulse width modulated signal based upon an input signal and a pulse width demodulation module configured to generate a demodulated pulse width signal. An isolator is configured to isolate the pulse width modulation module and the pulse width demodulation module and to generate isolated modulated pulse width signal based upon the pulse width modulated signal for the pulse width demodulation module to generate the demodulated pulse width signal. The programmable discrete input module also includes a first comparator and a second comparator for comparing the demodulated pulse width signal with a respective programmable reference and a digital filter configured to filter a comparison signal output by the first comparator or the second comparator to generate a discrete input signal.