Rockwell Automation 1747-PCINT API Software for 1746 I/O - Manual (Page 108)

6–54 Library of Routines OC_ReadInputImage
Publication 1747-6.5.3 June 1998
OC_ReadInputImage OC_ReadInputImage reads the current input image from the scanner.
Syntax:
int OC_ReadInputImage(HANDLE handle, WORD *inpimgcpy, int slotnum, WORD offset, WORD
len, WORD *imagebuf);
Parameters:
Description:
To guarantee that a series of calls to OC_ReadInputImage read data from a single input scan,
OC_ReadInputImage can first be called to read the entire input image into a local buffer pointed to by
imagebuf , with the inpimgcpy pointer set to NULL and slotnum set to -1. The imagebuf buffer can
then be passed as inpimgcpy in subsequent OC_ReadInputImage calls to retrieve the slot data from the
copy of the input image. This preserves input image file integrity across multiple calls to
OC_ReadInputImage.
If file integrity is not necessary, the host application can set inpimgcpy to NULL and access data directly
from shared memory.
Parameter: Description:
handle Must be a valid handle returned from OC_OpenScanner
inpimgcpy
If inpimgcpy is:
NULL OC_ReadInputImage reads data directly from the input image
in the scanner’s shared memory.
not NULL OC_ReadInputImage reads data from inpimgcpy which
contains a copy of the scanner’s input image.
slotnum
offset
len
If slotnum is:
positive input data for that slot is read into the array pointed to by
imagebuf . Then imagebuf contains len words of input
data starting at word offset of the module in the slot. Data
will not be read past the end of the input image for the slot.
-1 the entire input image is read into the array pointed to by
imagebuf , and offse t and len are ignored.
imagebuf
Must point to an array that is large enough to accept the amount of data
in the requested input image