Agilent Technologies N9344C Manuel de service télécharger pdf (Page 42)

34 Programmer’s Guide

4 Programming Example

Example Program

This example program queries a USB device for an identification string

and prints the results. Note that you must change the address if

something other than the default USB address value is required.

/*idn.c - program filename */

#include "visa.h"

#include <stdio.h>

void main ()

{

char buf[300]

ViSession viN9342C

ViStatus viSatus;

ViSession defaultRM;

/*Open session to USB device */

viOpenDefaultRM(&defaultRM);

viStatus=viOpen(defaultRM,"USB0::2391::8472::000

0000000::0::INSTR",VI_NULL,VI_NULL,&viN9342C);

/*Initialize device */

viPrintf(viN9342C, "*RST\n");

/*Send an *IDN? string to the device */

printf(viN9342C, "*IDN?\n");

/*Read results */

viRead This function synchronously reads raw data from the session specified by the vi

parameter and stores the result in location where buf is pointing. Only one

synchronous read operation can occur at any one time.

viRead(vi, buf, count, &retCount)

viClose This function must be used to close each session. When you close a device session, all

data structures that had been allocated for the session will be set free. If you close the

default resource manager session, all sessions opened using that resource manager

session will be closed.

viClose(vi);

viClose(defaultRM)

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Agilent Technologies N9344C Manuel de service Page 42