This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F28069M: SpinTAC velocity control error for bandwidth limit

Part Number: TMS320F28069M
Other Parts Discussed in Thread: MOTORWARE

Using SpinTAC velocity controller, I want to adjust the speed controller bandwidth. According to your user guide spruhj1g, there should be a max and min limit for this bandwidth. (Page 429 Table 12.2)

Statement is exactly as follows:

Set cfg.BwMax within [0, min(2000, 0.2/cfg.T)]

But I see that even if I increase Bandwith more than 2000 or more than 0.2/cfg.T, no error code is set. Moreover, in this cfg struct there is no variable called BwMax.

  1. Does the Table12.2 in your user guide belong to an older motorware etc.?( I am using motorware version 18.)
  2. Does that mean that there is no limit in your speed controller bandwidth? Or you have a limit but you do not display an error and you only limit Bandwidth inside your algorithm, is that the thing I see?
  • 1) It does seem that table12.2 is outdated. The value for bandwidth is stored Bw_radps in the ST_VelCtrl_t structure, and not limited by the cfg structure.

    2) unfortunately, TI does not have the source code for SpinTAC, which is owned by LineStream. We cannot look into the code to determine what in the end, if anything, limits bandwidth. In theory, bandwidth can be as high as your sampling frequency can support. I'm not sure there is any checking against the value that is stated in the user guide. I would recommend you set the bandwidth as appropriate of your system and test the solution

    Sean