This is description of the files that go together with MathWorks webinar gPID Control Made Easyh

1) pid_intro.m ? this script explains the basics of PID control.

2) engine_cl.mdl ? model to add PID Controller block to, show block options, and do the tuning.

3) data.mat ? file with test data to show system identification capabilities in PID Tuner.
a. Use this code in a shortcut to load and plot the data:

load data;
subplot(211);
plot(time,output);
ylabel('Speed');
grid;
subplot(212);
plot(time,input);
xlabel('time (seconds)');
ylabel('Throttle');
grid;

4) engine_cl_fixed_scaled.mdl ? the closed loop model with tuned PID controller. 
   PID Controller is implemented in discrete time with 16 bit fixed-point arithmetics.