National Instruments NI-488.2M Software Reference Manual page 56

Developing Your Application
Step 2. Clear the Device
Clear the device before you configure the device for your application. Clearing
the device resets its internal functions to a default state.
ibclr(ud);
if (ibsta & ERR) {
gpiberr("ibclr error");
}
Step 3. Configure the Device
After you open and clear the device, it is ready to receive commands. To
configure the instrument, you send device-specific commands using the ibwrt
function. Refer to the instrument user manual for the command bytes that work
with your instrument.
ibwrt(ud, "*RST; VAC; AUTO; TRIGGER 2; *SRE 16", 35L);
if (ibsta & ERR) {
gpiberr("ibwrt error");
}
The programming instruction in this example resets the multimeter (*RST). The
meter is instructed to measure the volts alternating current (VAC) using
autoranging (AUTO), to wait for a trigger from the GPIB interface board before
starting a measurement (TRIGGER 2), and to assert the SRQ line when the
measurement completes and the multimeter is ready to send the result (*SRE
16).
Step 4. Trigger the Device
If you configure the device to wait for a trigger, you must send a trigger
command to the device before reading the measurement value. Next, you must
instruct the device to send the next triggered reading to its GPIB output buffer.
ibtrg(ud);
if (ibsta & ERR) {
gpiberr("ibtrg error");
}
NI-488.2M SRM for OS/2 3-10 © National Instruments Corp.
Chapter 3