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.
