National Instruments GPIB-PC - Manual (Page 99)

BASICA/QuickBASIC GPIB-PC Function Calls Section Four A
GPIB-PC User Manual 4A-24 ©National Instruments Corp.
• IBONL - to cancel the I/O and reset the interface.
The asynchronous I/O started by IBCMDA terminates for the
same reasons IBCMD terminates.
An ECIC error results if the GPIB-PC is not CIC. If it is not
Active Controller, the GPIB-PC takes control and asserts
ATN prior to sending the command bytes. It remains
Active Controller afterward. The ENOL error does NOT
occur if there are no Listeners.
Board Example:
1. Address several devices for a broadcast message to follow
while testing for a high priority event to occur.
100 REM The interface board BRD0% at talk
110 REM address &H40 (ASCII @), addresses
120 REM nine Listeners at addresses &H31-
130 REM &H39 (ASCII 1-9) to receive the
140 REM broadcast message.
150 CMD$ = "?@123456789"
' UNL MTA
160 ' LAD1...LAD9
170 CALL IBCMDA (BRD0%,CMD$)
180 MASK% = $4100
' Wait for timeout or
190 ' I/O completion.
200 CALL EVENTTST ' Unspecified routine
210 ' to test and process
220 ' a high priority
230 ' event.
240 CALL IBWAIT (BRD0%,MASK%)
250 REM Loop until complete while no error
260 REM has occurred.
270 IF (IBSTA% AND &H100) = 0 GOTO 180