Communicating with a Single GPIB Instrument

If your system has only one instrument attached to each interface, the traditional NI-488.2 calls are probably sufficient for your programming needs. A typical GPIB application with a single instrument has three phases:

• Initialization—use ibdev to get a handle and use ibclr to clear the instrument.
• Device Communication—use ibwrt, ibrd, ibtrg, ibrsp, and ibwait to communicate with the instrument.
• Cleanup—use ibonl to put the handle offline.

For a detailed list, refer to the Device-Level Traditional NI-488.2 Calls topic.

For NI-488.2 applications that need to control the GPIB in non-typical ways, for example, to communicate with non-compliant GPIB instruments, there are a set of low-level calls that perform rudimentary GPIB applications. If you use these calls, you need to understand GPIB management details like how to address talkers and listeners. For some details on GPIB management, refer to the Learning More about GPIB topic.

These low-level calls are called board-level calls. They access the interface directly and require you to handle the addressing and bus management protocol. These calls give you the flexibility and control to handle situations such as the following:

• Communicating with non-compliant instruments
• Altering various low-level board configurations
• Managing the bus in non-typical ways

Board-level calls that an NI-488.2 application might use include the following: ibcmd, ibrd, ibwrt, and ibconfig. For a detailed list, refer to the Board-Level Traditional NI-488.2 Calls topic.