Simulink Control Design™ - MathWorks

• Step Amplitude: Specifies the amplitude of the injected step signal. In this example,
  choose 0.1 as well. Note that, if the plant has a single integrator, you need to choose
  not to estimate dc gain, and as a result, no step signal is injected to the plant.

Simulating Open-Loop PID Autotuner Block in Normal Mode

If you have a plant model built in Simulink, it is recommended to simulate the Open-Loop

PID Autotuner block against the plant model in the normal mode before using the block in

the external mode for real time tuning. Simulation will help you identify issues in signal

connection and block settings so that you can adjust them before generating code.

sim(mdl);

8 PID Autotuning