National Instruments 320682C

GPIB/GPIB-488.2 Library Chapter 4

LabWindows/CVI Standard Libraries 4-16 © National Instruments Corporation

Return Value

status integer

(short integer on

Windows 3.1)

The same value as the ibsta status variable.

Refer to your NI-488.2 or NI-488.2M user

manual for a description of the values of

ibsta status variable.

eventMask

The conditions upon which to invoke the callback function are specified as bits in the

eventMask parameter. The bits corresponds to the bits of the ibsta status word. This value

reflects a sum of one or more events. If any one of the conditions occur, the callback is called.

If, when you install the callback, one of the bits you have set in the mask is already TRUE, the

callback is scheduled immediately. For example, if you pass CMPL as the eventMask, and the

ibwait function would currently return a status word with CMPL set, the callback is scheduled

immediately.

If you are using a NI-488.2M (native 32-bit) driver then the following mask bits are valid:

• At the board level, you can specify any of the status word bits that can be specified in the

waitMask parameter to the ibwait function for a board, other than ERR. This includes

SRQI, END, CMPL, TIMO, CIC, and others.

• At the device level, you can specify any of the status word bits that can be specified in the

waitMask parameter to the ibwait function for a device, other than ERR. This includes

RQS, END, CMPL, and TIMO.

If you are using a NI-488.2 driver (Windows 3.1 or compatibility driver for Windows 95), then

the only following mask bits are valid:

SRQI or CMPL but not both.

SRQI, RQS, and Auto Serial Polling

If you want to install a callback for the SRQI (board-level) event, Auto Serial Polling must be

disabled. You can disable Auto Serial Polling with the following function call:

ibconfig (boardIndex, IbcAUTOPOLL, 0);

If you want to install a callback for the RQS (device-level) event, Auto Serial Polling must be

enabled for the board. You can enable Auto Serial Polling with the following function call:

ibconfig (boardIndex, IbcAUTOPOLL, 1);