TMS320F280049: Platform CLA software decode issue

Hi,

The module owner is OOO today. Please expect a response by Monday.

Thanks,

Veena

Hi Cherry,

Please find my answer below:

1) the two variables you are referring to are for debug use only (left over from development) and the code to update these variables was commented out during library generation. Hence these variable are supposed to be constant during operation.

2) You will need to make sure the excitation frequency, sampling frequency, CLA frequency, and the SAMPLING_TIME variable are all updated correctly. One thing to check is if the 6.25 us is long enough for CLA to process the function. You may want to plug a GPIO toggle into your CLA task and check if the frequency is correct and stable. 

Thanks.

Han

Hi Han,

Thanks for your support.

Han Zhang6 said:

You will need to make sure the excitation frequency, sampling frequency, CLA frequency, and the SAMPLING_TIME variable are all updated correctly.

It has been tested the processing function with GPIO, the processing time is around 1.5us and there is no overflow, the excitation frequency is fixed at 10KHz, and the feedback signal sin/cos is completely normal with the oscilloscope. The ADC trigger source and the CLA trigger source are the same.

1) What are the sampling frequency and SAMPLING_TIME respectively referring t0?

2) Are the parameters of the 12.5us and 6.25us processing cycles the same? For example: Kp,offsetFc,errorFc,piconFz,rslvrIn.firLag, etc. how to adjust these parameters? How does adjusting these parameters affect the output?

3) Could you help provide the debugging steps and reference documentations?

4) If a 15000RPM motor needs to be tested, how to adjust the parameters?

Note: The excitation is fixed 10 kHz, which is measured by the excitation modulator circuit, and the standard excitation signal is measured by the oscilloscope, and the feedback signal (sin,cos) is also handled by the hardware loop to the ADC channel directly into the DSP.

Thanks and regards,

Cherry

Hi,

May I know is there any follow up?

Thanks and regards,

Cherry

Hi Cherry,

1) Not sure what exactly you are asking. Main idea is to make sure all timing related setting are modified at the same time.

2) The CPU processing cycle per ISR / CLA task should be more or less the same, that is why I said you need to make sure the CLA have sufficient time to process the task after you made the sampling time to half. 

3) as suggested, you should first make sure the CLA task does not overrun by toggling some GPIO in the task.

4) This solution was mainly tested and optimized for low speed accuracy. IF you plan to run at high speed, maybe consider the resolver to digital solution in TIMD-02009 instead. That solution was optimized for high speed operation. 

Han