Appendix A Status Word Conditions - National Instruments NI-488.2M Software Reference Manual

Status Word Conditions Appendix A
ERR (dev, brd)
ERR is set in the status word following any call that results in an error.
You can determine the particular error by examining the error variable iberr.
ERR is cleared following any call that does not result in an error. Appendix B,
Error Codes and Solutions, describes both error codes that are recorded in
iberr and possible solutions.
TIMO (dev, brd)
TIMO indicates that the timeout period has been exceeded. TIMO is set in the
status word following an ibwait call if the TIMO bit of the ibwait mask
parameter is set and the time limit expires. TIMO is also set following any
synchronous I/O functions (for example, ibrd, ibwrt, ibcmd, Send,
Receive, and SendCmds) if a timeout occurs during one of these calls. TIMO
is cleared in all other circumstances.
END (dev, brd)
END indicates that either the GPIB EOI line has been asserted or that the EOS
byte has been received if the software is configured to terminate a read on an
EOS byte. If the GPIB board is performing a shadow handshake as a result of
the ibgts function, any other function can return a status word with the END
bit set if the END condition occurs before or during that call. END is cleared
when any I/O operation is initiated.
Some applications may need to know the exact I/O read termination mode of a
read operation: EOI by itself, the EOS character by itself, or EOI plus the EOS
character. You can use the ibconfig function (option
IbcEndBitIsNormal) to enable a mode in which the END bit is set only
when EOI is asserted. If the I/O operation completes because of the EOS
character by itself, END is not set. The application should check the last byte of
the received buffer to see if it is the EOS character.
SRQI (brd)
SRQI indicates that some GPIB device is requesting service. SRQI is set
whenever the GPIB board is CIC, the GPIB SRQ line is asserted, and the
automatic serial poll capability is disabled. SRQI is cleared when the GPIB
board ceases to be the CIC or when the GPIB SRQ line is unasserted.
NI-488.2M SRM for OS/2 A-2 © National Instruments Corp.