National Instruments NI-488.2 ユーザーズマニュアル

The following steps show you how to use the traditional NI-488.2 
device-level calls in your application. The NI-488.2 software includes the 

devquery

 source code example to demonstrate these principles.

Use 

ibdev

 to open a device handle. The 

ibdev

 function requires the 

following parameters:

•

Connect board index (typically 0, for 

GPIB0

).

•

Primary address for the GPIB instrument (refer to the instrument user 
manual or use the 

FindLstn

 function to dynamically determine the 

GPIB address of your GPIB device, as described in 

 in the 

section later in this chapter).

•

Secondary address for the GPIB instrument (0 if the GPIB instrument 
does not use secondary addressing).

•

Timeout period (typically set to T10s, which is 10 seconds).

•

End-of-transfer mode (typically set to 1 so that EOI is asserted with the 
last byte of writes).

•

EOS detection mode (typically 0 if the GPIB instrument does not use 
EOS characters).

A successful 

ibdev

 call returns a device handle, 

ud

, that is used for all 

device-level traditional NI-488.2 calls that communicate with the GPIB 
instrument.

Use 

ibclr

 to clear the device. This resets the device’s internal functions to 

the default state.

Communicate with the device by sending it the 

"*IDN?"

 query and then 

reading back the response. Many devices respond to this query by returning 
a description of the device. Refer to the documentation that came with your 
GPIB device to see specific instructions on the proper way to communicate 
with it.