cancel
Showing results for 
Search instead for 
Did you mean: 

STEVAL ESC001V1 Motor Pilot Graph

tej_sri_02
Associate II

I am trying to plot reference speed and measured speed on graph in Motor Pilot. But in graph why measured speed is coming before reference speed? I tried it at different speeds but response coming is same.

ref_meas.png

1 ACCEPTED SOLUTION

Accepted Solutions
cedric H
ST Employee

Hi @tej_sri_02 

The plot you are looking at is the register plot. It is not a real time plot. The information is collected by a pooling mechanism. Depending on the number of registers you plot, the Pilot will split the reading command into several accesses, that are at least 1 ms spaced, the atomicity is then absolutely not guarantee. On top of that, the MC Pilot draws lines between the various sampled, then at the end you can end up with such kind of artefact.

If you need to do graphical analysis, only the high frequency plot can be a root of trust. It is based on an asynchronous protocol and guarantee that all the data collected come from the same PWM cycle.

But, be assured that the system is always causal, and the answer never physically comes before the command ;) !

Regards

Cedric

View solution in original post

4 REPLIES 4
cedric H
ST Employee

Hi @tej_sri_02 

The plot you are looking at is the register plot. It is not a real time plot. The information is collected by a pooling mechanism. Depending on the number of registers you plot, the Pilot will split the reading command into several accesses, that are at least 1 ms spaced, the atomicity is then absolutely not guarantee. On top of that, the MC Pilot draws lines between the various sampled, then at the end you can end up with such kind of artefact.

If you need to do graphical analysis, only the high frequency plot can be a root of trust. It is based on an asynchronous protocol and guarantee that all the data collected come from the same PWM cycle.

But, be assured that the system is always causal, and the answer never physically comes before the command ;) !

Regards

Cedric

Hi Cedric,

Thanks for responding. Can we plot Measured and Reference Speed in HF Plot? I can't find corresponding registers of it in the window. Please help.

 

tej_sri_02_0-1751513758493.png

 

cedric H
ST Employee

Hi,

Those signals are updated on the medium frequency task, most of the time it is not really interesting to waste bandwidth to dump them in the high frequency plot. The main purpose is to have a global idea of the signal shape.

Now, if you need it, feel free to update the code (you can just replace the pointer of one of the list that you do not use)

Regards

Cedric

Thanks