Rockwell Automation 1747-PCIS API Software - Open Controller - Manual (Page 122)

Publication 1747-UM002A-US-P - June 2000
6-62 Library of Routines
Setting the output update mode to OUTUPD_CHANGE allows the
host application to signal the scanner to write outputs by calling
OC_WriteOutputImage. This setting allows the scanner’s minimum
scan time to be reduced (since it is only scanning inputs most of the
time), and is provided as a performance enhancement.
Setting the output update mode to OUTUPD_ALWAYS forces the
scanner to write outputs from the output image on every scan.
Return Value:
Considerations:
Supported in the DOS API library and the Windows NT API library
Example:
HANDLE Handle;
int retcode;
retcode = OC_SetOutputUpdateMode( Handle, OUTUPD_NEVER );
/* Must use OC_DemandOutputScan() function to send new output
data */
Name: Value: Description:
SUCCESS 0 conditional scan was set successfully
ERR_OCACCESS 2 handle does not have access to the scanner
ERR_OCINIT 5 scanner has not been initialized, see OC_InitScanner
ERR_OCPARAM 8 parameter contains invalid value