Difference between revisions of "KFLOP C Programs"

Revision as of 21:28, 18 October 2015

C Programs provide a powerful and flexible capability to perform almost any sequence of operations within KFLOP.   In most cases after you have tested and tuned all your hardware using the KMotion.exe setup program all the settings and initialization steps required for your system can be placed into an Initialization C Program so that your system can be fully initialized simply by executing the Initialization program.   Using a C Program offers full flexibility to initialize your system however and in whatever order you wish.  In most common cases an existing example can be used with simple modification of values specific to your system.  The KMotion.exe Setup program has some automatic capability to translate the Axes Screen Values that were determined by you during configuration and testing into C Code.

Initialization C Program

The Initialization C Program will normally perform operations of the following type:

• Enable/define any Option boards present (ie.    KStepPresent=TRUE;      // enable KSTEP input multiplexing)
• The setting of Axes parameters (ie.    ch0->Accel=200000; )
• Enable Axes (ie.EnableAxisDest(0,0); )
• Define the Coordinated Motion Axes (ie.    DefineCoordSystem(0,1,2,-1);  // define axes for XYZ
• Forever Loop to service any continuous requirements such as MPG, External Buttons, EStop, etc

Adding the configuration for a new Axis to your Initialization C Program:

1. Configure the Channel in KMotion.exe and verify that after Pushing "Enable" (which downloads and enables) it all works properly
2. On the Config/Flash Screen Push the "C Code To Clip Board" Button
3. Open your Initialization Program in the C Programs Screen
4. Position the cursor after the previous Axis settings
5. Right Mouse Click "Paste"
6. If desired also enable the axis by inserting EnableAxisDest(xx,0); where xx is the Axis number
7. Save the file
8. Test after a power cycle if the C Program initializes all Axes Properly

C Programming References

See the links listed here.

Simplest C Program

It is important to understand that any KFLOP C Program consists of a minimum number of parts as shown below. 

The first part is an #include statement which includes a

definition file that defines all the functionality available in KFLOP.  The KMotionDef.h file is included with every installation to define all the functions, variables, structures, and defines available in that Version.  It is located in the DSP_KFLOP subdirectory of the installation.  Open it with the KMotion.exe C Programs Screen to see what's available.

The next part is the "main" function. This is where execution of the program will actually begin. 

The last part is the code that is to be executed and belongs to the main function.  Curly brackets { } define the beginning and end of the function.  This example contains only one print statement to be executed. Note how the code within the curly brackets is indented (using a tab or spaces) to show that it belongs to the main function block.  This indentation is not required but helps readers see the program structure.  Instructions must end with a semicolon ';'.   Double forward slashes allow comments to be added at the end of an instruction.  

include "KMotionDef.h"
main()
{
    printf("Hello World!\n");  // send message to console
}

Basic Disk Read/Write

KFLOP has no file system on its own, but when connected to a PC with a PC App running it can do basic Disk Read or Write Operation.  Read capability was recently added in Version 4.33q.  There isn't any PC Keyboard access (getchar()).  See the KmotionDef.h file for supported functions:

// Note: standard C language printf
int printf(const char *format, ...);             // Print formatted string to console
int sprintf(char *s, const char *format, ...);     // Print formatted string to string

typedef int FILE;
FILE *fopen(const char*, const char*);           // Open a text file for writing on the PC (2nd param = "rt" or "wt")
int fprintf(FILE *f, const char * format, ...);           // Print formatted string to the PC's Disk File
int fclose(FILE *f);                           // Close the disk file on the PC

int Print(char *s);                              // Print a string to the console window
int PrintFloat(char *Format, double v);          // Print a double using printf format, ex "%8.3f\n"
int PrintInt(char *Format, int v);               // Print an integer using printf format, ex "result=%4d\n"
                                
int sscanf(const char *_str, const char *_fmt, ...); //scan string and convert to values

#define MAX_READ_DISK_LENGTH 1024 // max allowed length of disk file line length
extern volatile int read_disk_buffer_status; //status of read disk buffer 1=line available, 2=error, 3=eof
extern char read_disk_buffer[MAX_READ_DISK_LENGTH+1];
char *fgets(char *str, int n, FILE *file); //read string from PC disk file, str=buffer, n=buffer length, f=FILE pointer, returns NULL on error
int fscanf(FILE *f, const char *format, ...); //read sting from PC Disk file, convert values, returns number of items converted
int feof(FILE *f);   // End of file status for disk reading

Simple DiskReadWrite.c example

include "KMotionDef.h"

main()
{
    FILE *f;
    char s[256];
    double a=123.456,b=999.999,c=0.001;
    double x=0,y=0,z=0;
    int result;
    
    // write 3 comma separated values to a disk file
    f=fopen("c:\\Temp\\KFlopData.txt","wt");
    fprintf(s,"%f,%f,%f\n",a,b,c);
    fclose(f);
    
    // read them back in
    f=fopen("c:\\Temp\\KFlopData.txt","rt");
    if (!f)
    {
        printf("Unable to open file\n");
        return;
    }
    
    // read a line and convert 3 doubles
    result=fscanf(f,"%lf,%lf,%lf",&x,&y,&z);
    fclose(f);
    
    printf("# values converted = %d, x=%f, y=%f, z=%f\n",result,x,y,z);
}