Rockwell Automation 1747-PCIS API Software - Open Controller - Manual (Page 68)

Publication 1747-UM002A-US-P - June 2000
6-8 Library of Routines
The scanner updates the input image with data read from the
modules. Use OC_ReadInputImage to read data from the input image.
Return Value:
Considerations:
Supported in the DOS API library and the Windows NT API library
Example:
HANDLE Handle;
int retcode;
retcode = OC_DemandInputScan( Handle, OCWAIT );
OC_DemandOutputScan OC_DemandOutputScan forces the scanner to immediately perform
an output scan.
Syntax:
int OC_DemandOutputScan(HANDLE handle, int mode);
Parameters:
Description:
The scanner updates module outputs from the data in the output
image. Use OC_WriteOutputImage to write data to the output image.
Name: Value: Description:
SUCCESS 0 demand input request was successful
ERR_OCACCESS 2
handle
does not have access to scanner
ERR_OCRESPONSE 10 scanner did not respond to request
ERR_OCSCANCFG 14 scanner has not been configured
Parameter: Description:
handle Must be a valid handle returned from OC_OpenScanner
mode If
mode
is:
OCWAIT OC_DemandOutputScan waits for the output scan to
be completed before returning to the caller.
OCNOWAIT OC_DemandOutputScan returns immediately.