error extern "C"

[Lubaaa]

me in the Console application works.
In Form Aplications to report an error, the "extern", in header "USMCDLL.h"

Declaration in Motor.cpp:

// Motory.cpp : main project file.
#pragma warning(disable : 4996) // Disable warnings about some functions in VS 2005
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers

#include "stdafx.h"
#include <stdio.h>
#include <tchar.h>
#include <conio.h>
#include <process.h>
#include "USMCDLL.h"
#include "Form1.h"

using namespace System;
using namespace Motory;




Declaration in USMCDLL.h :

#pragma once

#include <windows.h>

// Please use the USMCDLL.lib to easely import functions from dll with "dllimport" (In Microsoft Visual Studio)
#ifdef USMCDLL_EXPORTS
#define USMCDLL_API __declspec(dllexport)
#else
#define USMCDLL_API __declspec(dllimport)
#endif
.
.
.
.
.(Code)
.
.
.
.
.(functions in the following error occurs) (Error is reflected in all of these features)
.
#ifdef __cplusplus // C++
extern "C" {
//
// The USMC_Init function initializes driver and returns devices information
//
USMCDLL_API DWORD USMC_Init( USMC_Devices &Str); // OUT - Array of structures describing all divices (may be NULL) MUST NOT be deleted

//
// The USMC_GetState function returns structure representing current state of device
//
USMCDLL_API DWORD USMC_GetState( DWORD Device, // IN - Device number
USMC_State &Str // OUT - Structure representing divice state
);
//
// The USMC_SaveParametersToFlash function saves current parameters of controller in static memory
// so thay can be loaded at start up time
//
USMCDLL_API DWORD USMC_SaveParametersToFlash( DWORD Device // IN - Device number
);
//
// The USMC_SetCurrentPosition function sets current position of controller
//
USMCDLL_API DWORD USMC_SetCurrentPosition( DWORD Device, // IN - Device number
int Position // IN - New position
);
//
// The USMC_GetMode function returns USMC_Mode structure last sent to device
//
USMCDLL_API DWORD USMC_GetMode( DWORD Device, // IN - Device number
USMC_Mode &Str // OUT - Structure representing some of divice parameters
);
//
// The USMC_SetMode function sets some of device parameters
//
USMCDLL_API DWORD USMC_SetMode( DWORD Device, // IN - Device number
USMC_Mode &Str // IN/OUT Structure representing some of divice parameters
);
//
// The USMC_GetParameters function returns USMC_Parameters structure last sent to device
//
USMCDLL_API DWORD USMC_GetParameters( DWORD Device, // IN - Device number
USMC_Parameters &Str // OUT - Structure representing some of divice parameters
);
//
// The USMC_SetParameters function sets some of divice parameters
//
USMCDLL_API DWORD USMC_SetParameters( DWORD Device, // IN - Device number
USMC_Parameters &Str // IN/OUT Structure representing some of divice parameters
);
//
// The USMC_GetStartParameters function returns USMC_StartParameters structure last sent to device
//
USMCDLL_API DWORD USMC_GetStartParameters( DWORD Device, // IN - Device number
USMC_StartParameters &Str // OUT - Structure representing start function parameters
);
//
// The USMC_Start function sets start parameters and starts motion
//
USMCDLL_API DWORD USMC_Start( DWORD Device, // IN - Device number
int DestPos, // IN - Destination position
float &Speed, // IN/OUT - Speed of rotation
USMC_StartParameters &Str // IN/OUT - Structure representing start function parameters
);
//
// The USMC_Stop function stops device
//
USMCDLL_API DWORD USMC_Stop( DWORD Device // IN - Device number
);
//
// The USMC_GetLastErr function return string representing last error
//
USMCDLL_API void USMC_GetLastErr( char *str, // OUT - String buffer
size_t len // IN - Lenght of that string buffer in bytes
);

//
// The USMC_GetDllVersion function returnes version values of USMCDLL.dll
//
USMCDLL_API void USMC_GetDllVersion( DWORD &dwHighVersion, // OUT - High Version Value
DWORD &dwLowVersion); // OUT - Low Version Value

//
// The USMC_Close function closes virtual driver window "microsmc.exe"
//
USMCDLL_API DWORD USMC_Close( void );

//
// The USMC_RestoreCurPos function checks AReset bit and if it is TRUE
// restores previous CurPos value
//
USMCDLL_API DWORD USMC_RestoreCurPos(DWORD Device // IN - Device number
);

// New For Firmware Version 2.4.1.0 (0x2410)

//
// The USMC_GetEncoderState function returns structure representing current position of encoder
//
USMCDLL_API DWORD USMC_GetEncoderState( DWORD Device, // IN - Device number
USMC_EncoderState &Str // IN/OUT Structure containing encoder state
);

// ~New For Firmware Version 2.4.1.0 (0x2410)

} // extern "C"
#else // C
DWORD USMC_Init( USMC_Devices *Str );
DWORD USMC_GetState( DWORD Device, USMC_State *Str );
DWORD USMC_SaveParametersToFlash( DWORD Device );
DWORD USMC_SetCurrentPosition( DWORD Device, int Position );
DWORD USMC_GetMode( DWORD Device, USMC_Mode *Str );
DWORD USMC_SetMode( DWORD Device, USMC_Mode *Str );
DWORD USMC_GetParameters( DWORD Device, USMC_Parameters *Str );
DWORD USMC_SetParameters( DWORD Device, USMC_Parameters *Str );
DWORD USMC_GetStartParameters( DWORD Device, USMC_StartParameters *Str );
DWORD USMC_Start( DWORD Device, int DestPos, float *Speed, USMC_StartParameters *Str);
DWORD USMC_Stop( DWORD Device );
void USMC_GetLastErr( char *str, size_t len );
DWORD USMC_Close( void );
DWORD USMC_GetEncoderState( DWORD Device, USMC_EncoderState *Str);
#endif // C/C++






!!!!! (I give only one message that error.)!!!!!
ERROR:

Motory.obj : error LNK2031: unable to generate p/invoke for "extern "C" unsigned long __clrcall USMC_GetEncoderState(unsigned long,struct USMC_EncoderState_st &)" (?USMC_GetEncoderState@@$$J0YMKKAAUUSMC_EncoderState_st@@@Z); calling convention missing in metadata
.
.
.
Motory.obj : error LNK2028: unresolved token (0A00000B) "int __clrcall Exit(void)" (?Exit@@$$FYMHXZ) referenced in function "void __clrcall Start(void)" (?Start@@$$FYMXXZ)
.
.
.
Motory.obj : error LNK2019: unresolved external symbol "void __clrcall zapisListBox1(unsigned long,char *,char *)" (?zapisListBox1@@$$FYMXKPAD0@Z) referenced in function "void __clrcall PrintDevices(struct USMC_Devices_st &)" (?PrintDevices@@$$FYMXAAUUSMC_Devices_st@@@Z)



Thank you for your help!

[Alex F]

Where is the code which is not compiled? And where is USMC_EncoderState structure declaration?

[Lubaaa]

Where is the code which is not compiled? And where is USMC_EncoderState structure declaration?

That is all in the head USMCDLL.h.
The header I have USMCDLL.lib and USMCDLL.dll. This need never be declared?
Errors occur when the translation function ( USMC_Init (USMC_Devices & Str) , USMC_GetState( DWORD Device, USMC_State &Str) ,...... )

The entire code in the header is:

#pragma once

#include <windows.h>

// Please use the USMCDLL.lib to easely import functions from dll with "dllimport" (In Microsoft Visual Studio)
#ifdef USMCDLL_EXPORTS
#define USMCDLL_API __declspec(dllexport)
#else
#define USMCDLL_API __declspec(dllimport)
#endif

// Structure representing connected devices
typedef struct USMC_Devices_st{
DWORD NOD; // Number of the devices ready to work

char **Serial; // Array of 16 byte ASCII strings
char **Version; // Array of 4 byte ASCII strings
} USMC_Devices; // Structure representing connected devices

// Structure representing some of divice parameters
typedef struct USMC_Parameters_st{
float AccelT; // Acceleration time (in ms)
float DecelT; // Deceleration time (in ms)
float PTimeout; // Time (in ms) after which current will be reduced to 60&#37; of normal
float BTimeout1; // Time (in ms) after which speed of step motor rotation will be equal to the one specified at
// BTO1P field (see below). (This parameter is used when controlling step motor using buttons)
float BTimeout2; //
float BTimeout3; //
float BTimeout4; //
float BTimeoutR; // Time (in ms) after which reset command will be performed
float BTimeoutD; // This field is reserved for future use
float MinP; // Speed (steps/sec) while performing reset operation. (This parameter is used when controlling
// step motor using buttons)
float BTO1P; // Speed (steps/sec) after BTIMEOUT 1 time have passed. (This parameter is used when controlling
// step motor using buttons)
float BTO2P; //
float BTO3P; //
float BTO4P; //
WORD MaxLoft; // Value in full steps that will be used performing backlash operation
DWORD StartPos; // Current Position Saved to FLASH (see Test MicroSMC.cpp)
WORD RTDelta; // Revolution distance – number of full steps per one full revolution
WORD RTMinError; // Number of full steps missed to raise the error flag
float MaxTemp; // Maximum allowed temperature (Celsius)
BYTE SynOUTP; // Duration of the output synchronization pulse
float LoftPeriod; // Speed of the last phase of the backlash operation.
float EncMult; // Should be <Encoder Steps per Evolution> / <SM Steps per Evolution> and should be integer multiplied by 0.25

BYTE Reserved[16]; // <Unused> File padding

} USMC_Parameters;

// Structure representing start function parameters
typedef struct USMC_StartParameters_st{
BYTE SDivisor; // Step is divided by this factor (1,2,4,8)
BOOL DefDir; // Direction for backlash operation (relative)
BOOL LoftEn; // Enable automatic backlash operation (works if slow start/stop mode is off)
BOOL SlStart; // If TRUE slow start/stop mode enabled.
BOOL WSyncIN; // If TRUE controller will wait for input synchronization signal to start
BOOL SyncOUTR; // If TRUE output synchronization counter will be reset
BOOL ForceLoft; // If TRUE and destination position is equal to the current position backlash operation will be performed.
BYTE Reserved[4]; // <Unused> File padding
} USMC_StartParameters;

// Structure representing some of divice parameters
typedef struct USMC_Mode_st{
BOOL PMode; // Turn off buttons (TRUE - buttons disabled)
BOOL PReg; // Current reduction regime (TRUE - regime is on)
BOOL ResetD; // Turn power off and make a whole step (TRUE - apply)
BOOL EMReset; // Quick power off
BOOL Tr1T; // Trailer 1 TRUE state (TRUE : +3/+5&#194;; FALSE : 0&#194
BOOL Tr2T; // Trailer 2 TRUE state (TRUE : +3/+5&#194;; FALSE : 0&#194
BOOL RotTrT; // Rotary Transducer TRUE state (TRUE : +3/+5&#194;; FALSE : 0&#194
BOOL TrSwap; // If TRUE, Trailers are treated to be swapped
BOOL Tr1En; // If TRUE Trailer 1 Operation Enabled
BOOL Tr2En; // If TRUE Trailer 2 Operation Enabled
BOOL RotTeEn; // If TRUE Rotary Transducer Operation Enabled
BOOL RotTrOp; // Rotary Transducer Operation Select (stop on error for TRUE)
BOOL Butt1T; // Button 1 TRUE state (TRUE : +3/+5&#194;; FALSE : 0&#194
BOOL Butt2T; // Button 2 TRUE state (TRUE : +3/+5&#194;; FALSE : 0&#194
BOOL ResetRT; // Reset Rotary Transducer Check Positions (need one full revolution before it can detect error)
BOOL SyncOUTEn; // If TRUE output syncronization enabled
BOOL SyncOUTR; // If TRUE output synchronization counter will be reset
BOOL SyncINOp; // Synchronization input mode:
// True - Step motor will move one time to the destination position
// False - Step motor will move multiple times by steps equal to the value destination position
DWORD SyncCount; // Number of steps after which synchronization output sygnal occures
BOOL SyncInvert; // Set to TRUE to invert output synchronization signal

BOOL EncoderEn; // Enable Encoder on pins {SYNCIN,ROTTR} - disables Synchronization input and Rotary Transducer
BOOL EncoderInv; // Invert Encoder Counter Direction
BOOL ResBEnc; // Reset <Encoder Position> and <SM Position in Encoder units> to 0
BOOL ResEnc; // Reset <SM Position in Encoder units> to <Encoder Position>

BYTE Reserved[8]; // <Unused> File padding

} USMC_Mode;

// Structure representing divice state
typedef struct USMC_State_st{
int CurPos; // Current position (in microsteps)
float Temp; // Current temperature of the driver
BYTE SDivisor; // Step is divided by this factor
BOOL Loft; // Indicates backlash status
BOOL FullPower; // If TRUE then full power.
BOOL CW_CCW; // Current direction. Relatively!
BOOL Power; // If TRUE then Step Motor is ON.
BOOL FullSpeed; // If TRUE then full speed. Valid in "Slow Start" mode only.
BOOL AReset; // TRUE After Device reset, FALSE after "Set Position".
BOOL RUN; // Indicates if step motor is rotating
BOOL SyncIN; // Logical state directly from input synchronization PIN
BOOL SyncOUT; // Logical state directly from output synchronization PIN
BOOL RotTr; // Indicates current rotary transducer press state
BOOL RotTrErr; // Indicates rotary transducer error flag
BOOL EmReset; // Indicates state of emergency disable button (local control)
BOOL Trailer1; // Indicates trailer 1 logical state.
BOOL Trailer2; // Indicates trailer 2 logical state.
float Voltage; // Input power source voltage (6-39V) -=24 version 0nly=-

BYTE Reserved[8]; // <Unused> File padding
} USMC_State;

// New For Firmware Version 2.4.1.0 (0x2410)
typedef struct USMC_EncoderState_st{
int EncoderPos; // Current position measured by encoder
int ECurPos; // Current position (in Encoder Steps) - Synchronized with request call

BYTE Reserved[8]; // <Unused> File padding
} USMC_EncoderState;

// ~New For Firmware Version 2.4.1.0 (0x2410)

typedef struct USMC_Info_st{
char serial[17];
DWORD dwVersion;
char DevName[32];
int CurPos, DestPos;
float Speed;
BOOL ErrState;

BYTE Reserved[16]; // <Unused> File padding
} USMC_Info;


#ifdef __cplusplus // C++
extern "C" {
//
// The USMC_Init function initializes driver and returns devices information
//
USMCDLL_API DWORD USMC_Init( USMC_Devices &Str); // OUT - Array of structures describing all divices (may be NULL) MUST NOT be deleted

//
// The USMC_GetState function returns structure representing current state of device
//
USMCDLL_API DWORD USMC_GetState( DWORD Device, // IN - Device number
USMC_State &Str // OUT - Structure representing divice state
);
//
// The USMC_SaveParametersToFlash function saves current parameters of controller in static memory
// so thay can be loaded at start up time
//
USMCDLL_API DWORD USMC_SaveParametersToFlash( DWORD Device // IN - Device number
);
//
// The USMC_SetCurrentPosition function sets current position of controller
//
USMCDLL_API DWORD USMC_SetCurrentPosition( DWORD Device, // IN - Device number
int Position // IN - New position
);
//
// The USMC_GetMode function returns USMC_Mode structure last sent to device
//
USMCDLL_API DWORD USMC_GetMode( DWORD Device, // IN - Device number
USMC_Mode &Str // OUT - Structure representing some of divice parameters
);
//
// The USMC_SetMode function sets some of device parameters
//
USMCDLL_API DWORD USMC_SetMode( DWORD Device, // IN - Device number
USMC_Mode &Str // IN/OUT Structure representing some of divice parameters
);
//
// The USMC_GetParameters function returns USMC_Parameters structure last sent to device
//
USMCDLL_API DWORD USMC_GetParameters( DWORD Device, // IN - Device number
USMC_Parameters &Str // OUT - Structure representing some of divice parameters
);
//
// The USMC_SetParameters function sets some of divice parameters
//
USMCDLL_API DWORD USMC_SetParameters( DWORD Device, // IN - Device number
USMC_Parameters &Str // IN/OUT Structure representing some of divice parameters
);
//
// The USMC_GetStartParameters function returns USMC_StartParameters structure last sent to device
//
USMCDLL_API DWORD USMC_GetStartParameters( DWORD Device, // IN - Device number
USMC_StartParameters &Str // OUT - Structure representing start function parameters
);
//
// The USMC_Start function sets start parameters and starts motion
//
USMCDLL_API DWORD USMC_Start( DWORD Device, // IN - Device number
int DestPos, // IN - Destination position
float &Speed, // IN/OUT - Speed of rotation
USMC_StartParameters &Str // IN/OUT - Structure representing start function parameters
);
//
// The USMC_Stop function stops device
//
USMCDLL_API DWORD USMC_Stop( DWORD Device // IN - Device number
);
//
// The USMC_GetLastErr function return string representing last error
//
USMCDLL_API void USMC_GetLastErr( char *str, // OUT - String buffer
size_t len // IN - Lenght of that string buffer in bytes
);

//
// The USMC_GetDllVersion function returnes version values of USMCDLL.dll
//
USMCDLL_API void USMC_GetDllVersion( DWORD &dwHighVersion, // OUT - High Version Value
DWORD &dwLowVersion); // OUT - Low Version Value

//
// The USMC_Close function closes virtual driver window "microsmc.exe"
//
USMCDLL_API DWORD USMC_Close( void );

//
// The USMC_RestoreCurPos function checks AReset bit and if it is TRUE
// restores previous CurPos value
//
USMCDLL_API DWORD USMC_RestoreCurPos(DWORD Device // IN - Device number
);

// New For Firmware Version 2.4.1.0 (0x2410)

//
// The USMC_GetEncoderState function returns structure representing current position of encoder
//
USMCDLL_API DWORD USMC_GetEncoderState( DWORD Device, // IN - Device number
USMC_EncoderState &Str // IN/OUT Structure containing encoder state
);

// ~New For Firmware Version 2.4.1.0 (0x2410)

} // extern "C"
#else // C
DWORD USMC_Init( USMC_Devices *Str );
DWORD USMC_GetState( DWORD Device, USMC_State *Str );
DWORD USMC_SaveParametersToFlash( DWORD Device );
DWORD USMC_SetCurrentPosition( DWORD Device, int Position );
DWORD USMC_GetMode( DWORD Device, USMC_Mode *Str );
DWORD USMC_SetMode( DWORD Device, USMC_Mode *Str );
DWORD USMC_GetParameters( DWORD Device, USMC_Parameters *Str );
DWORD USMC_SetParameters( DWORD Device, USMC_Parameters *Str );
DWORD USMC_GetStartParameters( DWORD Device, USMC_StartParameters *Str );
DWORD USMC_Start( DWORD Device, int DestPos, float *Speed, USMC_StartParameters *Str);
DWORD USMC_Stop( DWORD Device );
void USMC_GetLastErr( char *str, size_t len );
DWORD USMC_Close( void );
DWORD USMC_GetEncoderState( DWORD Device, USMC_EncoderState *Str);
#endif // C/C++

[Alex F]

Read MSDN topic "Linker Tools Error LNK2031" Possibly you need to declare USMC_GetEncoderState function as __cdecl explicitly. Error message contains __clrcall, which is default when managed code is compiled.

http://msdn.microsoft.com/en-us/library/ms173734.aspx

[Lubaaa]

Read MSDN topic "Linker Tools Error LNK2031" Possibly you need to declare USMC_GetEncoderState function as __cdecl explicitly. Error message contains __clrcall, which is default when managed code is compiled.

http://msdn.microsoft.com/en-us/library/ms173734.aspx

Thanks it works. I wrote it this way:

// USMCDLL.h - header file with declorations of USMCDLL.dll functions and used structures
// -SD
// Note::C++
// Use functions with reference arguments as in sample
// Note.C
// Use functions with address of operator in invoke expression: func(var1, &struct);
// (For Rev. 24) Will work correctly with firmware version 24.03 or better

#pragma once

#include <windows.h>

// Please use the USMCDLL.lib to easely import functions from dll with "dllimport" (In Microsoft Visual Studio)
#ifdef USMCDLL_EXPORTS
#define USMCDLL_API __declspec(dllexport)
#else
#define USMCDLL_API __declspec(dllimport)
#endif

// Structure representing connected devices
typedef struct USMC_Devices_st{
DWORD NOD; // Number of the devices ready to work

char **Serial; // Array of 16 byte ASCII strings
char **Version; // Array of 4 byte ASCII strings
} USMC_Devices; // Structure representing connected devices

// Structure representing some of divice parameters
typedef struct USMC_Parameters_st{
float AccelT; // Acceleration time (in ms)
float DecelT; // Deceleration time (in ms)
float PTimeout; // Time (in ms) after which current will be reduced to 60% of normal
float BTimeout1; // Time (in ms) after which speed of step motor rotation will be equal to the one specified at
// BTO1P field (see below). (This parameter is used when controlling step motor using buttons)
float BTimeout2; //
float BTimeout3; //
float BTimeout4; //
float BTimeoutR; // Time (in ms) after which reset command will be performed
float BTimeoutD; // This field is reserved for future use
float MinP; // Speed (steps/sec) while performing reset operation. (This parameter is used when controlling
// step motor using buttons)
float BTO1P; // Speed (steps/sec) after BTIMEOUT 1 time have passed. (This parameter is used when controlling
// step motor using buttons)
float BTO2P; //
float BTO3P; //
float BTO4P; //
WORD MaxLoft; // Value in full steps that will be used performing backlash operation
DWORD StartPos; // Current Position Saved to FLASH (see Test MicroSMC.cpp)
WORD RTDelta; // Revolution distance – number of full steps per one full revolution
WORD RTMinError; // Number of full steps missed to raise the error flag
float MaxTemp; // Maximum allowed temperature (Celsius)
BYTE SynOUTP; // Duration of the output synchronization pulse
float LoftPeriod; // Speed of the last phase of the backlash operation.
float EncMult; // Should be <Encoder Steps per Evolution> / <SM Steps per Evolution> and should be integer multiplied by 0.25

BYTE Reserved[16]; // <Unused> File padding

} USMC_Parameters;

// Structure representing start function parameters
typedef struct USMC_StartParameters_st{
BYTE SDivisor; // Step is divided by this factor (1,2,4,8)
BOOL DefDir; // Direction for backlash operation (relative)
BOOL LoftEn; // Enable automatic backlash operation (works if slow start/stop mode is off)
BOOL SlStart; // If TRUE slow start/stop mode enabled.
BOOL WSyncIN; // If TRUE controller will wait for input synchronization signal to start
BOOL SyncOUTR; // If TRUE output synchronization counter will be reset
BOOL ForceLoft; // If TRUE and destination position is equal to the current position backlash operation will be performed.
BYTE Reserved[4]; // <Unused> File padding
} USMC_StartParameters;

// Structure representing some of divice parameters
typedef struct USMC_Mode_st{
BOOL PMode; // Turn off buttons (TRUE - buttons disabled)
BOOL PReg; // Current reduction regime (TRUE - regime is on)
BOOL ResetD; // Turn power off and make a whole step (TRUE - apply)
BOOL EMReset; // Quick power off
BOOL Tr1T; // Trailer 1 TRUE state (TRUE : +3/+5Â; FALSE : 0Â)
BOOL Tr2T; // Trailer 2 TRUE state (TRUE : +3/+5Â; FALSE : 0Â)
BOOL RotTrT; // Rotary Transducer TRUE state (TRUE : +3/+5Â; FALSE : 0Â)
BOOL TrSwap; // If TRUE, Trailers are treated to be swapped
BOOL Tr1En; // If TRUE Trailer 1 Operation Enabled
BOOL Tr2En; // If TRUE Trailer 2 Operation Enabled
BOOL RotTeEn; // If TRUE Rotary Transducer Operation Enabled
BOOL RotTrOp; // Rotary Transducer Operation Select (stop on error for TRUE)
BOOL Butt1T; // Button 1 TRUE state (TRUE : +3/+5Â; FALSE : 0Â)
BOOL Butt2T; // Button 2 TRUE state (TRUE : +3/+5Â; FALSE : 0Â)
BOOL ResetRT; // Reset Rotary Transducer Check Positions (need one full revolution before it can detect error)
BOOL SyncOUTEn; // If TRUE output syncronization enabled
BOOL SyncOUTR; // If TRUE output synchronization counter will be reset
BOOL SyncINOp; // Synchronization input mode:
// True - Step motor will move one time to the destination position
// False - Step motor will move multiple times by steps equal to the value destination position
DWORD SyncCount; // Number of steps after which synchronization output sygnal occures
BOOL SyncInvert; // Set to TRUE to invert output synchronization signal

BOOL EncoderEn; // Enable Encoder on pins {SYNCIN,ROTTR} - disables Synchronization input and Rotary Transducer
BOOL EncoderInv; // Invert Encoder Counter Direction
BOOL ResBEnc; // Reset <Encoder Position> and <SM Position in Encoder units> to 0
BOOL ResEnc; // Reset <SM Position in Encoder units> to <Encoder Position>

BYTE Reserved[8]; // <Unused> File padding

} USMC_Mode;

// Structure representing divice state
typedef struct USMC_State_st{
int CurPos; // Current position (in microsteps)
float Temp; // Current temperature of the driver
BYTE SDivisor; // Step is divided by this factor
BOOL Loft; // Indicates backlash status
BOOL FullPower; // If TRUE then full power.
BOOL CW_CCW; // Current direction. Relatively!
BOOL Power; // If TRUE then Step Motor is ON.
BOOL FullSpeed; // If TRUE then full speed. Valid in "Slow Start" mode only.
BOOL AReset; // TRUE After Device reset, FALSE after "Set Position".
BOOL RUN; // Indicates if step motor is rotating
BOOL SyncIN; // Logical state directly from input synchronization PIN
BOOL SyncOUT; // Logical state directly from output synchronization PIN
BOOL RotTr; // Indicates current rotary transducer press state
BOOL RotTrErr; // Indicates rotary transducer error flag
BOOL EmReset; // Indicates state of emergency disable button (local control)
BOOL Trailer1; // Indicates trailer 1 logical state.
BOOL Trailer2; // Indicates trailer 2 logical state.
float Voltage; // Input power source voltage (6-39V) -=24 version 0nly=-

BYTE Reserved[8]; // <Unused> File padding
} USMC_State;

// New For Firmware Version 2.4.1.0 (0x2410)
typedef struct USMC_EncoderState_st{
int EncoderPos; // Current position measured by encoder
int ECurPos; // Current position (in Encoder Steps) - Synchronized with request call

BYTE Reserved[8]; // <Unused> File padding
} USMC_EncoderState;

// ~New For Firmware Version 2.4.1.0 (0x2410)

typedef struct USMC_Info_st{
char serial[17];
DWORD dwVersion;
char DevName[32];
int CurPos, DestPos;
float Speed;
BOOL ErrState;

BYTE Reserved[16]; // <Unused> File padding
} USMC_Info;


#ifdef __cplusplus // C++
extern "C" {
//
// The USMC_Init function initializes driver and returns devices information
//
USMCDLL_API DWORD __cdecl USMC_Init( USMC_Devices &Str); // OUT - Array of structures describing all divices (may be NULL) MUST NOT be deleted

//
// The USMC_GetState function returns structure representing current state of device
//
USMCDLL_API DWORD __cdecl USMC_GetState( DWORD Device, // IN - Device number
USMC_State &Str // OUT - Structure representing divice state
);
//
// The USMC_SaveParametersToFlash function saves current parameters of controller in static memory
// so thay can be loaded at start up time
//
USMCDLL_API DWORD __cdecl USMC_SaveParametersToFlash( DWORD Device // IN - Device number
);
//
// The USMC_SetCurrentPosition function sets current position of controller
//
USMCDLL_API DWORD __cdecl USMC_SetCurrentPosition( DWORD Device, // IN - Device number
int Position // IN - New position
);
//
// The USMC_GetMode function returns USMC_Mode structure last sent to device
//
USMCDLL_API DWORD __cdecl USMC_GetMode( DWORD Device, // IN - Device number
USMC_Mode &Str // OUT - Structure representing some of divice parameters
);
//
// The USMC_SetMode function sets some of device parameters
//
USMCDLL_API DWORD __cdecl USMC_SetMode( DWORD Device, // IN - Device number
USMC_Mode &Str // IN/OUT Structure representing some of divice parameters
);
//
// The USMC_GetParameters function returns USMC_Parameters structure last sent to device
//
USMCDLL_API DWORD __cdecl USMC_GetParameters( DWORD Device, // IN - Device number
USMC_Parameters &Str // OUT - Structure representing some of divice parameters
);
//
// The USMC_SetParameters function sets some of divice parameters
//
USMCDLL_API DWORD __cdecl USMC_SetParameters( DWORD Device, // IN - Device number
USMC_Parameters &Str // IN/OUT Structure representing some of divice parameters
);
//
// The USMC_GetStartParameters function returns USMC_StartParameters structure last sent to device
//
USMCDLL_API DWORD __cdecl USMC_GetStartParameters( DWORD Device, // IN - Device number
USMC_StartParameters &Str // OUT - Structure representing start function parameters
);
//
// The USMC_Start function sets start parameters and starts motion
//
USMCDLL_API DWORD __cdecl USMC_Start( DWORD Device, // IN - Device number
int DestPos, // IN - Destination position
float &Speed, // IN/OUT - Speed of rotation
USMC_StartParameters &Str // IN/OUT - Structure representing start function parameters
);
//
// The USMC_Stop function stops device
//
USMCDLL_API DWORD __cdecl USMC_Stop( DWORD Device // IN - Device number
);
//
// The USMC_GetLastErr function return string representing last error
//
USMCDLL_API void __cdecl USMC_GetLastErr( char *str, // OUT - String buffer
size_t len // IN - Lenght of that string buffer in bytes
);

//
// The USMC_GetDllVersion function returnes version values of USMCDLL.dll
//
USMCDLL_API void __cdecl USMC_GetDllVersion( DWORD &dwHighVersion, // OUT - High Version Value
DWORD &dwLowVersion); // OUT - Low Version Value

//
// The USMC_Close function closes virtual driver window "microsmc.exe"
//
USMCDLL_API DWORD __cdecl USMC_Close( void );

//
// The USMC_RestoreCurPos function checks AReset bit and if it is TRUE
// restores previous CurPos value
//
USMCDLL_API DWORD __cdecl USMC_RestoreCurPos(DWORD Device // IN - Device number
);

// New For Firmware Version 2.4.1.0 (0x2410)

//
// The USMC_GetEncoderState function returns structure representing current position of encoder
//
USMCDLL_API DWORD __cdecl USMC_GetEncoderState( DWORD Device, // IN - Device number
USMC_EncoderState &Str // IN/OUT Structure containing encoder state
);

// ~New For Firmware Version 2.4.1.0 (0x2410)

} // extern "C"
#else // C
DWORD USMC_Init( USMC_Devices *Str );
DWORD USMC_GetState( DWORD Device, USMC_State *Str );
DWORD USMC_SaveParametersToFlash( DWORD Device );
DWORD USMC_SetCurrentPosition( DWORD Device, int Position );
DWORD USMC_GetMode( DWORD Device, USMC_Mode *Str );
DWORD USMC_SetMode( DWORD Device, USMC_Mode *Str );
DWORD USMC_GetParameters( DWORD Device, USMC_Parameters *Str );
DWORD USMC_SetParameters( DWORD Device, USMC_Parameters *Str );
DWORD USMC_GetStartParameters( DWORD Device, USMC_StartParameters *Str );
DWORD USMC_Start( DWORD Device, int DestPos, float *Speed, USMC_StartParameters *Str);
DWORD USMC_Stop( DWORD Device );
void USMC_GetLastErr( char *str, size_t len );
DWORD USMC_Close( void );
DWORD USMC_GetEncoderState( DWORD Device, USMC_EncoderState *Str);
#endif // C/C++


Perhaps the code is good and not just a coincidence?