Patent ID: 7680549

Claim:
A field device for diagnosing operation of an industrial process control or monitoring system, comprising: an input coupled to the industrial process configured to receive a process signal; a microprocessor configured to implement: an enhanced statistical parameter module comprising: a first statistical parameter module having a first statistical parameter output related to a statistical parameter of the received process signal, wherein the statistical parameter is selected from the group of statistical parameters comprising minimum, maximum, range, mean, root mean squared, standard deviation, Q 25 , Q 50 and Q 75 ; a filter implementing a plurality of filter algorithms having a filter output related to a filtered value of the received process signal based upon at least one of the filter algorithms; a second statistical parameter module having a second statistical parameter output related to a statistical parameter of the filter output, the second statistical parameter selected from the group of statistical parameters consisting of minimum, maximum, range, mean, root mean squared, standard deviation, Q 25 , Q 50 and Q 75 ; and a diagnostic module configured to diagnose operation of the industrial process based upon the first and the second statistical parameters; an output configured to provide a diagnostic output from diagnostic module.