Defaultwssrdhandler (status, count), Defaultwsswrthandler (status, count), Genproterror (proterr) – National Instruments NI-VXI User Manual

Page 56: Getwsscmdhandler ()

Advertising
background image

Chapter 3 Software Overview

NI-VXI User Manual

3-18

© National Instruments Corporation

DefaultWSSLcmdHandler

calls

GenProtError

with a protocol error

code of

UnSupCom

for every Longword Serial command received.

DefaultWSSrdHandler (status, count)

DefaultWSSrdHandler

is the default handler for the

WSSrd

interrupt,

which

InitVXIlibrary

automatically installs when it initializes the

NI-VXI software. When

WSSrd

reaches the specified count or an END

bit, or an error occurs, it calls the

WSSrd

interrupt handler with the

status of the call. The default handler sets the global variables

WSSrdDone

,

WSSrdDoneStatus

, and

WSSrdDoneCount

. You can

use the variable

WSSrdDone

to poll until the operation is complete.

Afterwards, you can inspect

WSSrdDoneStatus

and

WSSrdDoneCount

to see the outcome of the call. If you want, you can

use the

SetWSSrdHandler

function to install an alternate handler.

DefaultWSSwrtHandler (status, count)

DefaultWSSwrtHandler

is the default handler for the

WSSwrt

interrupt, which

InitVXIlibrary

automatically installs when it

initializes the NI-VXI software. When

WSSwrt

reaches the specified

count or an error occurs, it calls the

WSSwrt

interrupt handler with the

status of the call. The default handler sets the global variables

WSSwrtDone

,

WSSwrtDoneStatus

, and

WSSwrtDoneCount

. You can

use the variable

WSSwrtDone

to poll until the operation is complete.

Afterwards, you can inspect

WSSwrtDoneStatus

and

WSSwrtDoneCount

to see the outcome of the call. If you want, you

can use the

SetWSSwrtHandler

function to install an alternate

handler.

GenProtError (proterr)

In response to a Word Serial Protocol Error, the application should call

GenProtError

to generate the error. Generating the error consists of

preparing the response to a future Read Protocol Error query (saving
the value in a global variable) and setting the ERR* bit in the local
Response register. The

RespProtError

function actually generates

the response when the Read Protocol Error query is received later.

GetWSScmdHandler ()

GetWSScmdHandler

returns the address of the current

WSScmd

interrupt handler function. While Word Serial operations are enabled,
the

WSScmd

interrupt handler is called whenever a Word Serial

command (other than BREQ and BAV) is received.

Advertising