A PID dual rate controller implementation over a networked control system

In networked control systems (NCS) environments is usual to find restrictions with data-acquisition frequency. If the control action updating can be faster than the output measurement, the use of a dual rate controller is a natural solution. Due to PIDs are useful controllers in industrial applications, in this paper a dual rate PID controller is designed splitting a conventional PID into two parts acting at different sampling rates. Its implementation over a specific NCS scenario (Profibus DP) is assumed. The study includes a description of a NCS, the introduction of a dual rate design methodology for PID controllers and also an analysis that validates the real implementation using this approach. Finally, theoretical and practical results are shown too.