topic Re: MagniV MCAT data Type Question in S12 / MagniV Microcontrollers

MagniV MCAT data Type Question

SW_Park — Wed, 12 Jan 2022 11:41:44 GMT

Nmax = 8000rpm at MCAT
When Speed Required = 8000 is input, the following error occurs.
The data type doesn't seem right. Please check how to set it up.

Re: MagniV MCAT data Type Question

tomasfedor — Mon, 17 Jan 2022 07:58:53 GMT

Hi SW_Park,

Could you please specify in which example the issue occurred?

Here are 3 items you can verify:

1) Freemaster variable limit.

open freemaster variable and check limit in tab modifying.

(You can find more about variables in Freemaster documentation section 4.2 Variables)

2) is proper elf flashed in MCU:
in order to be able to translate value to raw format fmScale.speed_n_m must exist in project.

3) if you want to apply a change in MCAT tab "Parameters" the project needs to be compiled and flashed.

ïn Mcat click "store data"' button

generate output file

compile and flash project from CW.

Generated constants (PMSM_appconfig.h)

are initialized in stateReset and stateInit

Freemaster scale constants are initialized in stateReset

Best regards,

Tomas Fedor

System Application Engineer

Re: MagniV MCAT data Type Question

SW_Park — Tue, 18 Jan 2022 01:58:49 GMT

Thank you for answer. Once the problem has been resolved.
In addition, please inquire about variable setting.

1) I do not understand the reason for setting " x2: 1000 " even if I look at the manual.
2) y2: fmScale.speed_n_m = Nmax X 1000
-> Why? Multiply by 1000?

Re: MagniV MCAT data Type Question

tomasfedor — Tue, 18 Jan 2022 08:33:03 GMT

Hi SW_Park,

When you define Freemaster variable, Freemaster can do a service of "further post-processing numeric
transformation". In other words some formula can be applied before a variable is written to a microprocessor and it is also applied in the reverse direction when the variable is read from microcontroller.

In case of the ManiV mc example Freemaster variable Speed Required is linked with microprocessor variable drvFOC.pospeControl.wRotElReq. This variable is in fraction format Q0.15 <-1,1). From the GUI perspective it is better to see Speed Required in physical dimension RPM. This is where we can use "Real Type transformation" feature of Freemaster.

Linear transformation is the type useful for this usecase and we can pick out of 2 forms:

"Linear ax + b" or "Lin: two points" because in coordinate geometry of a straight line the line can be defined:

1) by gradient and offset "Linear ax + b"

2) by 2 points

in case of Speed Required:

point 1 X=0, Y=0

point 2 X=1000, Y=fmScale.speed_n_m

Best regards,

Tomas Fedor

System Application Engineer

Re: MagniV MCAT data Type Question

SW_Park — Tue, 18 Jan 2022 10:55:34 GMT

Hi...
Nmax = 8000 [rpm] -> Application scale
Speed Required = 4000 [rpm] -> Freemaster variable

Then,
microprocessor variable
drvFOC.pospeControl.wRotElReq = FRAC16(0.4999847412);

Is that right?

If yes, does "Lin: two points" mean coordinates to convert to a float variable?
So, is the multiplication by 1000 for the compensation of decimal arithmetic?

then
point 1 X=0, Y=0
I think " point 2 X=0, Y=fmScale.speed_n_m = 8000 " can also be used.

Re: MagniV MCAT data Type Question

tomasfedor — Tue, 18 Jan 2022 12:48:53 GMT

Hi SW_Park,

Here is process of Freemaster variable Speed Required from MagniV MC example:

Linear transformation:

X1= 0 , Y1 = 0
X2= 1000, Y2 =fmScale.speed_n_m = FM_SPEED_RPM_MEC_SCALE = 4500 000

means y = x*4500 where y is what we see in the GUI (Speed Required) and X is output from the transformation.
In other words it is transformation between range <-1,1) and <-4500,4500)

Variable settings:

Variable is set as signed fraction format Q0.15 so it takes output from the transformation "range <-1,1)" and recalculates it to correct binary form of Q0.15.
Note: if output from transformation is out of range Q0.15 (for example 1.5) you get an error.

Best regards,

Tomas Fedor

System Application Engineer

Re: MagniV MCAT data Type Question

lama — Tue, 18 Jan 2022 13:00:58 GMT

Hi,

the question is now more FreeMASTERr oriented. Because of this I would like to suggest you to continue at Freemaster specialized forum where specialist for FreeMASTER are able to provide answer.

https://community.nxp.com/t5/FreeMASTER/bd-p/freemaster

Best regards,

Ladislav