摘要 |
<p>A device in a process control system includes a memory for storing a series of sensed process variables and command outputs representative of a learned process cycle. Comparison circuitry compares recent process information to learned process information stored in the memory and responsively provides a validity output signal. A method includes learning a cycle of a process to provide learned process information which comprises stored process variables and stored control signals over a time period, measuring a process variable in the process and responsively calculating the control output, storing the process variable in the control output to provide recent process information, and comparing the recent process information to the learned process information and responsively providing a validity output signal.</p> |