Ibtrap – National Instruments GPIB-PC User Manual

Page 156

Section Four A

BASICA/QuickBASIC GPIB-PC Function Calls

©National Instruments Corp.

4A-81

GPIB-PC User Manual

BASICA/QuickBASIC

IBTRAP

Purpose:

Alter applications monitor trap and display modes

Format:

CALL IBTRAP (MASK%,DISPLAY%)

Remarks:

MASK%

specifies a bit mask with the same bit assignments

as the mask used with the function

IBWAIT

. Each

MASK%

bit is set, cleared to trap, or cleared not to trap,
respectively, when the corresponding bit appears in the
status word after a GPIB call. If all the bits are set, then
every GPIB call is trapped.

MODE%

determines when the recording and trapping occur.

The valid values are:

Turn monitor off. No recording or trapping
occurs.

Turn record on. All calls are recorded but
no trapping occurs.

Turn record and trap on. All calls are
recorded and the monitor is displayed
whenever a trap condition occurs.

If an error occurs during this call, the ERR bit of

IBSTA

will be set and

IBERR

will be one of the following:

Applications monitor not installed.

Invalid monitor mode.

4 (EARG)

IBTRAP

not supported by installed

handler.

Otherwise,

IBERR

will contain the previous mask value.

Refer to Section Six for more information.