National Instruments GPIB-PC - Manual (Page 211)

Section Five IBIC
©National Instruments Corp. 5-23 GPIB-PC User Manual
Turn on the remote enable signal (REN).
Example:
GPIB0:
[0130] (cmpl cic atn)
previous value: 0
ibsre 1
Set up the addressing for the device to listen and the computer to talk.
The question mark (
? ) and underscore ( _ ) characters represent the
unlisten (UNL) and untalk (UNT) commands, respectively. These must
be sent first in every
IBCMD function to reset the bus addressing. The @
character represents the GPIB-PC board's talk address. This was
calculated using the Multiline Interface Message chart in Appendix A.
The GPIB-PC board is at GPIB primary address 0. Moving across to the
Talk address column, the appropriate ASCII character is an
@ character.
In a similar manner the ! character represents the listen address of the
device which in this case is assumed to be at GPIB primary address 1.
The Multiline Interface Command chart indicates that the listen address
for a device at primary address of 1 is an
! character.
Example:
GPIB:
[0188] (cmpl lok cic atn tacs)
count: 4
ibcmd "?_@!"