MATLAB: Is there a delay in triggering ISR when HRPWM-period is enabled in ePWM block

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Why the Interrupt Service Routine (ISR) invoking is delayed when the "HRPWM Period enable* *(HRPWM-period)" is enabled in the ePWM Block?

Best Answer

The reason for the delay is the Scale Factor Optimizing (SFO) library used. When the option "HRPWM Period enable* *(HRPWM-period)" is enabled, the Micro Edge Positioner (MEP) values are recalculated at each step causing the delay. This information can be found at the following page.
<http://www.mathworks.com/help/supportpkg/texasinstrumentsc2000/ug/c280xc2802xc2803xc2805xc2806xc28x3xc2834xf28m3xepwm.html http://www.mathworks.com/help/supportpkg/texasinstrumentsc2000/ug/c280xc2802xc2803xc2805xc2806xc28x3xc2834xf28m3xepwm.html
>
In order to overcome this issue please follow the below mentioned steps.
1. Disable "HRPWM Period enable (HRPWM-period)"
2. Enable "HRPWM Period enable (HRPWM-duty)"
3. Disable "Use scale factor optimizer (SFO) software"
4. Disable "Enable auto convert"

Related Solutions

MATLAB: Is the result zero when I compute the linearization with respect to a variable time delay

The reason why the answer is zero is because of the specific way the "Variable Time Delay" block is treated during linearization. The input to this block is not meant to be used as "Input perturbation" and as a result the linearization is not accurate. For an alternative implementation, please look at the attached model. As opposed to using the "Variable Time Delay" block, one could use the "Clock" block and add or subtract the delay time as necessary. In this approach, when the variable time delay is set as "Input perturbation", the result is the expected one. The example models the linearization of "y = sin(t-t0)" where "t0" is the value of the variable time delay.

MATLAB: How to create custom code suggestions for class functions in MATLAB live scripts

It is possible to use code suggestions with ordinary class member functions.

The only difference is you must account for the first method argument being a reference to the class.

The first argument passed to a MATLAB class member function is a reference to the object. In that sense, the following two function calls are equivalent:

classObj.func(val)
func(classObj, val)

For more information on this, please see:

https://www.mathworks.com/help/matlab/matlab_oop/specifying-methods-and-functions.html

When creating the 'functionsSignatures.json', be sure to include an input for the class object.

Here is an example 'functionsSignature.json' snippet for a class which has static and ordinary member functions:

{
      "BasicClass.BasicClass":
      {
          "inputs":
          [
              {"name":"inputVal", "kind":"required", "type":["numeric"], "purpose":"Constructor with value to initalize with."}
          ]
      },
      "BasicClass.printString":
      {
          "inputs":
          [
              {"name":"inputString", "kind":"required", "type":["string"], "purpose":"String to print to screen."}
          ]
      },
      "BasicClass.multBy":
      {
          "inputs":
          [
              {"name":"obj", "kind":"required", "type":["BasicClass"], "purpose":"BasicClass object to run function on."},
              {"name":"multVal", "kind":"required", "type":["numeric"], "purpose":"Will multiply the initial value by multVal."}
          ]
      }
  }

In the example, "printString" is static, while "multBy" is a traditional member function.

Moreover, once you have written the JSON file, you can also verify it by executing the following command in the MATLAB Command Window:

>> validateFunctionSignaturesJSON

You will find more information about this function in the documentation:

https://www.mathworks.com/help/matlab/ref/validatefunctionsignaturesjson.html

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Related Solutions

MATLAB: Is the result zero when I compute the linearization with respect to a variable time delay

MATLAB: How to create custom code suggestions for class functions in MATLAB live scripts

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