National Instruments NI-VXI

Chapter 3 Software Overview

AcknowledgeTrig (controller, line)

AcknowledgeTrig performs the required trigger acknowledgments

for the ASYNC or SEMI-SYNC VXI-defined protocol, as configured

via the EnableTrigSense function.

DefaultTrigHandler (controller, line, type)

DefaultTrigHandler is the sample handler for the receiving

acknowledges and sensing triggers, and is automatically installed after

a call to InitVXIlibrary. After a call to EnableTrigSense for a

particular VXI trigger line protocol, the trigger handler for a specific

trigger line is called when the sourced trigger is sensed from the

sourcing device. If the configured VXI trigger protocol requires an

acknowledgment (either ASYNC or SEMI-SYNC), you must call the

AcknowledgeTrig function to perform the acknowledgment.

DefaultTrigHandler calls the AcknowledgeTrig function if the

type parameter specifies that an acknowledge interrupt occurred.

Otherwise, DefaultTrigHandler performs no operations.

DefaultTrigHandler2 (controller, line, type)

DefaultTrigHandler2 is a sample handler for receiving

trigger interrupt sources similar to DefaultTrigHandler.

DefaultTrigHandler2 performs no operations. Any required

acknowledgments must be performed by the application.

DisableTrigSense (controller, line)

DisableTrigSense unconfigures and desensitizes the triggering

hardware that was enabled by the EnableTrigSense function to

generate interrupts when any VXI-defined trigger protocol is sensed on

the specified trigger line.

EnableTrigSense (controller, line, prot)

EnableTrigSense configures and sensitizes the triggering hardware

to generate interrupts when the specified VXI-defined trigger protocol

is sensed on the specified trigger line. When EnableTrigSense has

configured and enabled the triggering hardware to generate interrupts,

and the specified trigger protocol is sensed, a local CPU interrupt is

generated. The trigger handler installed is automatically called when a

trigger interrupt occurs.