viInstallHandler(3)

HP-UX

NAME

viInstallHandler − Installs handlers on sessions for event callbacks

SYNOPSIS

viInstallHandler(ViSession vi, ViEventType eventType,
ViHndlr handler, ViAddr userHandle);

Description

This function allows applications to install handlers on sessions for event callbacks. The handler specified in the handler parameter is installed along with previously installed handlers for the specified event. Applications can specify a value in the userHandle parameter that is passed to the handler on its invocation. VTL identifies handlers uniquely using the handler reference and this value.

Parameters

vi An input parameter. Unique logical identifier to a session.

eventType An input parameter. Logical event identifier.

handler An input parameter. Interpreted as a valid reference to a handler to be installed by an application.

userHandle An input parameter. A value specified by an application that can be used for identifying handlers uniquely for an event type.

The following events can be enabled:

VI_EVENT_SERVICE_REQ Notification that a device is requesting service.

VI_EVENT_VXI_SIGP Notification that a VXI signal or VXI interrupt has been received from a device.

VI_EVENT_TRIG Notification that a hardware trigger was received from a device.

Return Values

This is the functional return status. It returns either a completion code or an error code as follows.

VI_SUCCESS Event handler installed successfully.

VI_ERROR_INV_SESSION VI_ERROR_INV_OBJECT The given session or object reference is invalid (both are the same value).

VI_ERROR_INV_EVENT Specified event type is not supported by the resource.

VI_ERROR_INV_HNDLR_REF The given handler reference is invalid.

VI_ERROR_HNDLR_NINSTALLED The handler was not installed. This may be returned if an application attempts to install multiple handlers for the same event on the same session.

AUTHOR

viInstallHandler was developed by HP

Hewlett-Packard Comapny — September 29, 1999

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