National Instruments GPIB-PC - Manual (Page 160)

Section Four A BASICA/QuickBASIC GPIB-PC Function Calls
©National Instruments Corp. 4A-85 GPIB-PC User Manual
Table 4A.4 - Wait Mask Layout
Mnemonic Bit Hex Description
ERR 15 8000 GPIB error
TIMO 14 4000 Time limit exceeded
END 13 2000 GPIB-PC detected END or EOS
SRQI 12 1000 SRQ on
RQS 11 800 Device requesting service
CMPL 8 100 I/O completed
LOK 7 80 GPIB-PC is in lockout state
REM 6 40 GPIB-PC is in remote state
CIC 5 20 GPIB-PC is CIC
ATN 4 10 Attention is asserted
TACS 3 8 GPIB-PC is Talker
LACS 2 4 GPIB-PC is Listener
DTAS 1 2 GPIB-PC is in device trigger state
DCAS 0 1 GPIB-PC is in device clear state
Device IBWAIT Function:
When BD% specifies a device, only the ERR, TIMO, END, RQS, and
CMPL bits of the wait mask and status word are applicable. On an
IBWAIT for RQS, each time the GPIB SRQ line is asserted, the access
board of the specified device serially polls all devices on its GPIB and
saves the responses, until the status byte returned by the device being
waited for indicates that it was the device requesting service (bit &H40
is set in the status byte). Note that an
IBWAIT on RQS should only be
done on those devices that respond to serial polls. If the TIMO bit of the
mask is also set,
IBWAIT returns if SRQ is not asserted within the
device's timeout period. The serial polls are conducted with the board
functions
IBCMD and IBRD .
Board IBWAIT Function:
When BD% specifies a board, all bits of the wait mask and status word
are applicable except RQS.