0204-20 SMHCCA Heating Cooling Controller

Example Projects > 0204 Function Blocks AUTOTUNING > 0204-20 SMHCCA Heating Cooling Controller

SMHCCA - Heating Cooling

This folder contains the source files for the demonstration project on heating/cooling control with possibility of respecting asymetric heating/cooling processes. In the project, controller called SMHCCA was used. The SMHCCA is especially dedicated to heating/cooling control and it's greatest advantage is integrated autotuner.

The SMHCCA controller is suitable for system control with one or two binary inputs, when user requires hight robustness with lower control precision. The controller uses discrete sliding mode control. A unique feature of the SMHCCA controller is the possibility of automatic tune during the first approaching the setpoint value. This possibility can be turn on by setting inputs TMODE=TAFF="on" (=1). The simultaneous procesess of approaching and controller tuning can be started by the pulse on input TUNE. Parameters of controller will be autoset in the initial phase of approaching the setpoint value and controller will be switched into automatic mode after that.

Timing of the project

The algorithm runs each 100 milliseconds (0.01 s). See the EXEC function block,
tick x ntick0 = 0.005 x 2 = 0.01


  • REXYGEN Runtime Core must be installed and running on the target device.
  • License for advanced blocks library must be installed.

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.
  • Select the SMHCCA block and enable online monitoring (Target->Watch Selection).
  • Tick the BSTATE parameter of the MP_TUNE to switch on the autotuning experiment.
  • Open trend diagnostic window for the block TRND_sp_pv and observe the tuning progress. The process is slow, so it will take a while.
  • After successful tuning, parameters of the regulator will be automatically set. Parameters can be observed at p1-p6 outputs of the SMHCCA regulator.
  • Try the automatic control with CNR_sp.


Additional information

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