PIDU - Split Range Control

This folder contains the source files for the demonstration project on cooperation of two valves controlled by one PID controller. Valves can be used for pipes flow control and the process model (MDL_PROCESS block) can be an estimate of mass dynamics.

The first valve is coarse and causes a huge changes of manipulated variable (mv). The seccond - fine valve is dedicated to compensation small deviations caused by noise. The fine valve is usually faster and more precise. Weight ratio of both valves is defined in GAIN_FV and GAIN_CV blocks. The coarse valve makes 80% and fine valve 20% from overall manipulated variable by default.

Fine valve is linearly opened with the range of mv = <0; 0.2>. At the value mv = 0.2 is the valve fully opened. The coarse valve is getting opened on and CNDR_COARSE blocks.

Timing of the project

The algorithm runs each 100 milliseconds (0.1 s). See the EXEC function block,
tick x ntick0 = 0.05 x 2 = 0.1

Prerequisites

• REXYGEN Runtime Core must be installed and running on the target device.

Running the example

• The exec.mdl file is the project main file.
• Open it with REXYGEN Studio, compile and download it to the target device.
• Switch to Watch mode and observe the algorithm.
• Open trend diagnostic window for the block TRND_Split_Range.
• Change the set point (sp) to 3. The fine valve will reach the high saturation limit and the coarse valve will be used for control.
• Change the set point to 1. The fine valve will be used for control and the coarse valve will be at the low saturation limit.
• Change the set point to 2. Both valves will be used for control.

Documentation

• Press F1 for help on the selected function block in the REXYGEN Studio.
• PIDU function block documentation
• Function blocks of REXYGEN
• REXYGEN Studio User Guide
• Complete documentation of REXYGEN

Additional information

• Visit the REXYGEN webpage for more information about the example projects and developing advanced automation and control solutions using REXYGEN.