PIDU with PWM

The source files illustrating the control of a process with binary On/Off actuator in REXYGEN are located in this folder. Process is controlled with a PID controller. Analog output from PID is converted into binary format with pulse-width modulation in the block PWM, which run with other period than PID. The faster triggering the PWM ensures better resolution of manipulated variable and thus more precise control. The PWM block and model of the process are running with period 0.1s. The PID controller is running with period 2s.

Timing of the project

The algorithm runs each 100 milliseconds (0.1 s). See the EXEC function block,
tick x ntick0 = 0.025 x 4 = 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_Loop for observing proces value, manipulated variable and set point trends. You can choose the TRND_PWM for watching signals from PWM block too.
• Change the set point (CNR_sp) in range from 0 to 10.
• Observe the controller action (PIDU:mv) and the process reaction (MDL_PROCESS:y) in trend TRND_Loop and PWM action in TRND_PWM.
• Change the set point (CNR_sp) in range from -10 to 0 and observe system behavior again.

Documentation

• Press F1 for help on the selected function block in the REXYGEN Studio.
• PIDU function block documentation
• PWM 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.