National Instruments NI-488.2 - Manual (Page 99)

Appendix B Status Word Conditions
© National Instruments Corporation B-3 NI-488.2 User Manual
SRQI (brd)
SRQI indicates that a GPIB device is requesting service. SRQI is set when
the GPIB interface is CIC and the GPIB SRQ line is asserted. SRQI is
cleared either when the GPIB interface ceases to be the CIC or when the
GPIB SRQ line is unasserted.
RQS (dev)
RQS appears in the status word only after a device-level call and indicates
that the device is requesting service. RQS is set whenever one or more
positive serial poll response bytes have been received from the device.
A positive serial poll response byte always has bit 6 asserted. Automatic
serial polling must be enabled (it is enabled by default) for RQS to
automatically appear in
ibsta . You can also wait for a device to request
service regardless of the state of automatic serial polling by calling ibwait
with a mask that contains RQS. Do not issue an ibwait call on RQS for a
device that does not respond to serial polls. Use ibrsp to acquire the serial
poll response byte that was received. RQS is cleared when all of the stored
serial poll response bytes have been reported to you through the
ibrsp
function.
CMPL (dev, brd)
CMPL indicates the condition of I/O operations. It is set whenever an
I/O operation is complete. CMPL is cleared while the I/O operation is
in progress.
LOK (brd)
LOK indicates whether the interface is in a lockout state. While LOK is set,
the
EnableLocal or ibloc call is inoperative for that interface. LOK is
set whenever the GPIB interface detects that the Local Lockout (LLO)
message has been sent either by the GPIB interface or by another
Controller. LOK is cleared when the System Controller unasserts the
Remote Enable (REN) GPIB line.