Rockwell-automation 1747-PCIS API Software - Open Controller Uživatelský manuál stáhnout pdf (Strana 71)

Publication 1747-UM002A-US-P - June 2000

Library of Routines 6-11

Parameters:

Description:

There are three types of end-of-scan messages:

End-of-scan messages are generated from the scanner to the API via

interrupts after each scan. The scan rate is controlled by the

OC_SetScanTime function and end-of-scan interrupts are generated at

the scan rate. Enabling end-of-scan messages can affect the

performance of the application due to the overhead incurred in

processing these interrupts. An alternative method to synchronize with

the scanner’s I/O scan is to monitor the scanner watchdog register,

which is incremented at the end of each timed I/O scan. See

OC_GetScannerWatchdogCount.

Return Value:

Considerations:

Supported in the DOS API library and the Windows NT API library

Parameter: Description:

handle Must be a valid handle returned from OC_OpenScanner

mode If

mode is:

EOSMSG_ENABLE the scanner generates an end-of-scan

message after each scan. Use the

OC_PollScanner function to retrieve

end-of-scan messages.

EOSMSG_DISABLE the scanner does not generate End-of-scan

messages. End-of-scan messages are

disabled after the scanner has been reset.

This type of message: Is generated after:

OCMSG_EOS_DMDIN a OC_DemandInputScan command has

completed

OCMSG_EOS_DMDOUT a OC_DemandOutputScan command has

completed

OCMSG_EOS each timed I/O scan

Name: Value: Description:

SUCCESS 0 notification was generated successfully

ERR_OCACCESS 2

handle does not have access to scanner

ERR_OCINIT 5 scanner has not been initialized, see OC_InitScanner

ERR_OCPARAM 8 parameter contains invalid value

1 2 ... 66 67 68 69 70 71 72 73 74 75 76 ... 173 174

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Rockwell-automation 1747-PCIS API Software - Open Controller Uživatelský manuál Strana 71