Table b-1. bit definitions – Measurement Computing GPIB-488 User Manual
Page 104
Appendix B
IBSTA
B-2
GPIB-488
Table B-1. Bit Definitions
Bit
Description
ERR
GPIB Error. If this bit = 1, an error has occurred during the call. An error code
describing the exact error is returned to the
iberr
variable. See
Appendix C,
for more information. ERR is cleared following any call
that does not result in an error.
Check for errors after each call. If an undetected error occurs early in your
program, it may not be apparent until later in the program, when it is more
difficult to isolate.
TIMO
Timeout Error. If this bit = 1, a time-out has occurred. Some of the conditions
which may result in this are:
A synchronous I/O function exceeds the programmed timeout.
An
ibwait
has exceeded the time limit value.
This bit is cleared (set to 0) during all other operations.
Different timeout periods may be set for each device. You can set the timeout
values either by using the configuration utility or in your program by using the
ibtmo
function.
END (END)
END or EOS Detected. If this bit = 1, EOI has been asserted or an EOS byte
has been detected. If the GPIB Interface board has been programmed through
an
ibgts
to perform shadow handshaking, any other routine can set this bit to
one.
This bit is cleared (set to 0) whenever an I/O operation is initiated.
SRQI
SRQ Interrupt Received. If this bit = 1, a device or Controller is requesting
service. This bit is set upon the following conditions:
•
The GPIB Interface Board is the Active
Controller.
•
The GPIB SRQ line is asserted.
•
Automatic serial poll capability is disabled.
This bit is cleared (= 0) upon the following conditions:
•
The GPIB Interface Board is no longer the Active
Controller.
•
The GPIB SRQ line is unasserted.