Rockwell Automation 6008-SV2R VMEbus remote I/O Scanner - Manual (Page 169)

Chapter
Programming the Scanner
8
8Ć35
Programming Examples
/*
**
** READ_INPUT_WORD() –– read from selected input image table entry
**
**
This routine reads the specified entry in the discrete input table.
**
**
parameters: pointer to channel structure
** target rack number
** target IO group word (0–7)
** pointer to rack/IO group word value
** return values: none
**
*/
void
read_input_word (channel far *chan, int rack, int iogrp,
unsigned short far *rval)
{
unsigned short far *wordptr;
unsigned offset = ((rack * 8) + iogrp);
/* map channel & establish pointers */
map_channel(chan);
wordptr = (unsigned short far *) chan–>InputTable;
wordptr += offset;
/* read the word */
*rval = *wordptr;
/* unmap the channel */
unmap_channel(chan);
return;
}