Appendix B Status Word Conditions
© National Instruments Corporation B-3 NI-488.2 User Manual for Windows
SRQI (brd)SRQI indicates that a GPIB device is requesting service. SRQI is set
whenever the GPIB interface is CIC, the GPIB SRQ line is asserted, and the
automatic serial poll capability is disabled. 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.