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Entry type: Application example Entry ID: 62154322, Entry date: 05/13/2019

3-Point Stepper Control with SIMATIC S7-1200/S7-1500

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STEP 7 (TIA Portal) offers you the technology object "PID_3Step" to control valves and actuators with integrating behavior for SIMATIC S7-1200/S7-1500 PLC. The handling of this PID controller with self tuning is shown using a mixer tap as an example.
The valve of a mixer tap will be controlled according to a desired given temperature.
A three-way mixing valve with valve actuator is used. The valve is digital controlled in both directions. This is referred to as a 3-point stepper control.
Varying the valve position can yield any mixing ratio of hot and cold entering water and so the water outlet temperature.

Figure 01

The application on hand provides quick configuration and commissioning of your mixer tap.
The application also contains a simulation of the controlled system, which enables familiarizing yourself with all functions of "PID_3Step".
The following features can be conveniently operated via KTP900 Basic PN:

  • Switching between automatic and manual mode
  • Transition time measurement of the valve
  • Visualization of the valve position
  • Trend curves of setpoint, process value and output value
  • Switching between the real controlled system and the simulation
  • Disturbance value control in simulation mode
  • Specifying the behavior in the case of errors and their simulation
  • Specifying the deadband width for energy saving operation
  • Manually specified control parameter and automatic tuning
  • Online monitoring of the "PID_3Step" controller block
  • Modifying the configuration during runtime


  • PID Control
    Simple programming with configurable blocks.
    Simple commissioning through automatic calculation of the control parameters for optimal control quality and clear signal monitoring with trace function.
  • Integrated PID control
    Specialized stepper controller for integrated actuators (e.g. valves).
  • Auto tuning
    Innovative auto tuning with two different tuning methods for automatic calculation of the control parameters: pretuning and fine tuning during runtime.


  • No additional hardware and software required (due to simulation of the controlled system).
  • Time saving due to simple automatic control parameter tuning for optimal control quality (PID controller).

Version 2.0 for TIA Portal V15.1 or higher
  Documentation "Three-step control with PID_3Step" (2,7 MB)
 Registrierung notwendig  Example project for SIMATIC S7-1200 (3,1 MB)
 Registrierung notwendig  Example project for SIMATIC S7-1500 (3,1 MB)

Further Information
Function Manual: “SIMATIC S7-1200/S7-1500 PID Control”

Application example: "PID control with PID_Compact for SIMATIC S7-1200/S7-1500"
Application example: “Closed-Loop Control of Simulated Controlled Systems in the S7-1500 with PID_Compact V2"
Application example: “Single and Multi Loop Controller Structures (Cascade Control) with PID_Temp"
Application example "Multi-Zone Control with PID_Temp for SIMATIC S7-1200/S7-1500"

Last Changes
Update to TIA Portal V15.1 + upgrade for SIMATIC S7-1500