Agilent Technologies 34970A manual ++ Example dacout.c

Chapter 7 Application Programs

Example Programs for C and C++

C / C++ Example: dac_out.c

/* dac_out.c /***************************************************************************

* Required: 34907A Multifunction Module in slot 200; VISA library		*
* This program uses the VISA library to communicate with the	34970A.	*
* The program queries slot 200 and displays the response. It	then resets	*

* the instrument and sends the value ’voltage’ to the DAC on channel 205. *

****************************************************************************/

#include <visa.h>
#include <stdio.h>
#include <string.h>
#define ADDR "9"	/* Set GPIB address for instrument */
void main ()
{
ViSession defaultRM;	/* Resource manager id */
ViSession dac;	/* Identifies instrument */
char reply_string [256];	/* String returned from instrument */
char Visa_address[40];	/* VISA address sent to module */
double voltage;	/* Value of voltage sent to DAC */

/* Build the address required to open communication with GPIB card. The address format looks like this "GPIB0::9::INSTR". */

strcpy(Visa_address,"GPIB0::"); strcat(Visa_address, ADDR); strcat(Visa_address, "::INSTR");

/* Open communication (session) with the 34970A */

viOpenDefaultRM (&defaultRM);

viOpen (defaultRM, Visa_address,VI_NULL,VI_NULL, &dac);

/* Query the module id in slot 200; Read response and print. */ viPrintf (dac, "SYST:CTYPE? 200\n");

viScanf (dac, "%s", &reply_string);

printf("Instrument identification string:\n %s\n\n", reply_string);

viPrintf (dac, "*RST\n");	/*	Set	power-on	condition */
voltage = 5;	/*	Set	variable	to voltage setting */

viPrintf (dac, "SOURCE:VOLTAGE %f,(@205)\n",voltage); /* Set output voltage */ /* Close communication session */

viClose (dac); viClose (defaultRM);

}

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