National Instruments GPIB-MAC User Manual page 100

November 1985
When #count is not specified, the GPIB-MAC
recognizes the end of the data string when it sees a
carriage return or a line feed. #count is required when
your data string contains embedded carriage return or
If you specify an address list, the GPIB-MAC must be
CIC to perform the addressing. If this is the first
function you call that requires GPIB controller
capability, and you have not disabled System Controller
capability with rsc, the GPIB-MAC sends Interface
Clear (IFC) to make itself CIC.
If you passed control to some other GPIB device,
control must be passed back to you or you must send
Otherwise, the ECIC error will be posted.
If you do not give an alist and the GPIB-MAC is not
CIC, it assumes it will be addressed by the controller. If
you do not give an alist and the GPIB-MAC is CIC, it
addresses itself as talker and assumes the listeners are
already addressed.
The first part of this programming message, up to
<CR>, is buffered, meaning the GPIB-MAC will not act
upon it until it receives <CR>. The string that follows
the first line is piped to the GPIB, non-buffered. This
allows you to send a string larger than the GPIB-MAC's
internal buffer with one programming message.
The GPIB-MAC aborts the GPIB write if it receives
Device Clear or Selected Device Clear and its Listen
Address. The GPIB-MAC aborts the GPIB write and
records the EABO error if, at any time during the GPIB
write, the time limit set for I/O functions expires. This
89 SECTION FOUR - FUNCTIONS