Need help with s-function error messages

Hello! I would like to generate a s-function from c-code. It is a state feedback controller with 5 inputs and 1 output. I am new to both, c-code and s-functions... so here are my error messages:

### Start Compiling cp_state_feedback_sfunc mex('cp_state_feedback_sfunc.c', 'E:\Master\SEM 2\ESPRO\Matlab Models\cpcntrl_final\u_feedback_control2.c', '-IE:\Master\SEM 2\ESPRO\Matlab Models\cpcntrl_final')

Writing library for cp_state_feedback_sfunc.mexw32 c:\users\espro\appdata\local\temp\mex_pkknwq\cp_state_feedback_sfunc.obj .text: undefined reference to '_u_feedback_control2'

C:\PROGRA~1\MATLAB\R2013B\BIN\MEX.PL: Error: Link of 'cp_state_feedback_sfunc.mexw32' failed.

Unable to complete successfully.

Error in legacycode.LCT/compile (line 268)

Error in legacycode.LCT.legacyCodeImpl (line 84)

Error in legacy_code (line 87)

[varargout{1:nargout}] = legacycode.LCT.legacyCodeImpl(action, varargin{1:end});

Error in legacy (line 11) legacy_code('compile', def)

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my .h file

----------------------------------------------------------------------------------- #ifndef STATE_FEEDBACK2_H_

#define STATE_FEEDBACK2_H_

#define k_x 54 //0.000324

#define k_xdot 245 //0.0145

#define k_a -802 //-0.0495

#define k_adot -11976 // -0.730

#define prefilter 9

#define fixed_point_shift 14

#define fixed_point_shift_pre 12

typedef unsigned char u8;

typedef unsigned short u16;

typedef unsigned long u32;

typedef unsigned long long u64;

typedef char s8;

typedef short s16;

typedef long s32;

typedef long long s64;

s16 u_state_control(short ref, short Last_Cposit, short speed, short Pangle, short Angvel);

#endif /* STATE_FEEDBACK_H_ */

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my .c file

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#include "state_feedback2.h"

s16 u_state_control( short ref, short Last_Cposit, short speed, short Pangle, short Angvel)

{

s32 Ref_val = ref;

s32 u_cntr;

s32 prefiltered;

prefiltered = ((Ref_val * prefilter) >> fixed_point_shift_pre );

u_cntr = ((k_adot * Angvel)>> fixed_point_shift ) + ((k_a * Pangle)>> fixed_point_shift) +

((k_xdot * speed)>> fixed_point_shift ) + ((k_x * Last_Cposit)>> fixed_point_shift );

return (s16)u_cntr;

}

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LCT

----------------------------------------------------------------------------------- def = legacy_code('initialize');

def.SourceFiles = {'u_feedback_control2.c'};

def.HeaderFiles = {'state_feedback2.h'};

def.SFunctionName = 'cp_state_feedback_sfunc';

def.OutputFcnSpec = 'int16 y1 = u_feedback_control2(int16 u1, int16 u2, int16 u3, int16 u4, int16 u5)'

legacy_code('sfcn_cmex_generate', def)

legacy_code('compile', def)

legacy_code('slblock_generate', def)

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I would really appreciate if somebody could tell me what these error messages mean and how i can avoid them.

Thanks alot

Daniel

Answer 1

[Kaustubha Govind]

Not sure if it's a typo in the question, but from your def.OutputFcnSpec, it looks like you are attempting to call u_feedback_control2, when the function defined in your header is u_state_control,

Answer 2

[Daniel]

Of course... Thx. now it is working