Rockwell Automation 1747-PCINT API Software for 1746 I/O - Manual (Page 104)

6–50 Library of Routines OC_PollScanner
Publication 1747-6.5.3 June 1998
OC_PollScanner OC_PollScanner reads module I/O interrupt, discrete input interrupt, and end-of-
scan notification messages from the scanner.
Syntax:
int OC_PollScanner(HANDLE handle, int MsgFilter, MSGBUF *msgbuf);
Parameters:
Description:
The MSGBUF structure is defined as:
typedef struct {
BYTE MsgID;
BYTE MsgData[4];
} MSGBUF;
The MsgID member of the msgbuf structure will be one of the following values:
Parameter: Description:
handle Must be a valid handle returned from OC_OpenScanner
MsgFilter
If MsgFilter is:
OCMSG_DIINT
OCMSG_IOINT,
OCMSG_EOS,
OC_PollScanner returns a message only
OCMSG_EOS_DMDIN of the corresponding type, if any
or
OCMSG_EOS_DMDOUT
OCMSG_ANY
OC_PollScanner searches for a
message, in
the order OCMSG_DIINT, OCMSG_IOINT,
OCMSG_EOS_DMDIN,
OCMSG_EOS_DMDOUT, then
OCMSG_EOS, from any of the sources.
msgbuf A structure that contains scanner messages
This value: Means:
OCMSG_NONE No message available
OCMSG_IOINIT I/O module interrupt message, see OC_SetModuleInterrupt
OCMSG_DIINT Discrete input interrupt message, see OC_ConfigureDII
OCMSG_EOS_DMDIN
End-of-scan notification message from OC_DemandInputScan command,
see OC_EnableEOSNotify
OCMSG_EOS_DMDOUT
End-of-scan notification message from OC_DemandOutputScan
command, see OC_EnableEOSNotify
OCMSG_EOS
End-of-scan notification message for timed I/O scan, see
OC_EnableEOSNotify