Cross-correlation clarifies the relationships between PID control loops. With accurate measurement of process signals, loops can be compared against each other using a time-shift to identify those loops that are correlated. The resulting detail indicates whether one loop leads or lags another, and it enables production staff to quickly zoom in on the source of control loop performance issues.
PlantESP’s correlation matrix graphically displays the many relationships on either a unit operation or plant-wide basis. Its use of color-coding provides a clear indication of leading loops that are upstream in the process (Red) versus lagging loops located downstream (Blue). PlantESP also specifies the timing of that relationship.
PlantESP makes it easy to switch from one advanced forensic tool to another. Control loops selected in the Cross-Correlation matrix can be evaluated in the Power Spectrum viewer with the touch of a button.