Agilent Technologies FS2010 Guía de usuario descargar pdf (Pagina 117)

Programming via GPIB and VXI 4

Agilent VISA User’s Guide 117

• They provide the best performance when transferring

large blocks of data.

• They support both block and FIFO mode.

The disadvantage of viMoveIn/viMoveOut calls is that they

have higher initial overhead than viPeek/viPoke.

Sample: Using VXI Memory I/O

This program demonstrates using various types of VXI

memory I/O.

/* memio.c

This example program demonstrates the use of

various memory I/O methods in VISA. */

#include <visa.h>

#include <stdlib.h>

#include <stdio.h>

#define VXI_INST "VXI0::24::INSTR"

void main () {

ViSession defaultRM, vi;

ViAddr address;

ViUInt16 accessMode;

unsigned short *memPtr16;

unsigned short id_reg;

unsigned short devtype_reg;

unsigned short memArray[2];

/*Open default resource manager and session

to instr*/

viOpenDefaultRM (&defaultRM);

viOpen defaultRM, VXI_INST, VI_NULL,VI_NULL,

&vi);

================================================

Low level memory I/O = viPeek16 = direct

memory dereference (when allowed)

================================================

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Agilent Technologies FS2010 Guía de usuario Pagina 117