Chapter 3
Developing Your Application
© National Instruments Corp.
3-3
NI-488.2M SRM for OS/2
NI-488 Board-Level Functions
Board-level functions are low-level functions that perform rudimentary GPIB
operations. Board-level functions access the interface board directly and require
you to handle the addressing and bus management protocol.
In cases when the device-level functions might not meet your needs,
board-level functions give you the flexibility and control to handle situations
such as the following:
•
Communicating with noncompliant (non-IEEE 488.2) devices
•
Altering various low-level board configurations
•
Managing the bus in non-typical ways
The NI-488 board-level functions are compatible with, and can be interspersed
within, sequences of NI-488.2 routines. When you use
board-level functions within a sequence of NI-488.2 routines, you do not need a
prior call to
ibfind
. You simply substitute the board index as
the first parameter of the board-level function call. With this flexibility, you can
handle non-standard or unusual situations that you cannot resolve using
NI-488.2M routines only.
Using NI-488.2 Routines: Multiple Boards and/or Multiple Devices
When your system includes a board that must access more than one device, use
the NI-488.2 routines. NI-488.2 routines can perform the following tasks with a
single call:
•
Find all of the Listeners on the bus
•
Configure the attached instruments
•
Find a device requesting service
•
Determine the state of the SRQ line
•
Wait for SRQ to be asserted
•
Address multiple devices