Rockwell Automation 1747-PCIS API Software - Open Controller - Manual (Page 42)

Publication 1747-UM002A-US-P - June 2000
3-10 Developing Applications
/*
** Read first Input word
*/
retcode = OC_ReadInputImage( Handle, NULL, input_slot, 0, 1, &wData );
if ( retcode != SUCCESS )
{
printf( ”\nERROR: OC_ReadInputImage failed: %d\n”, retcode );
Ioexit( 1 );
}
printf( ”\n\n First input image data word --> 0x%04x \n”, wData );
delay( 3000 );
/*
** Write to the first Output word
*/
printf( ”\n\n Incrementing first discrete output word. \n” );
for ( wData=0; wData < 256; wData++)
{
retcode = OC_WriteOutputImage( Handle, NULL, output_slot, 0, 1,
&wData );
if ( retcode != SUCCESS )
{
printf(”\nERROR: OC_WriteOutputImage failed: %d\n”,
retcode);
Ioexit(1);
}
delay ( 10 );
}
/*
** Must always close the scanner before exiting
*/
OC_CloseScanner( Handle );
printf( ”\n\n Program is done! \n\n” );
} /* end main() */
/************************************************************************
*
*
Name: Ioexit
*
*
Description:
*
*
Common error handling routine. This routine displays any
* extended error and exits the program.
*
*
Arguments:
* retcode : int ( input )
* This error code is passed to the exit() routine.
*
*
External effects:
* The program is terminated.
*
*
Return value:
* none
*
************************************************************************/
void Ioexit( int retcode )
{
OCEXTERR exterr;
char *msg;
if (OC_GetExtendedError(Handle, &exterr) == SUCCESS)
{
if ( exterr.ErrorCode != 0 )
{
Scan I/O