Agilent Technologies E1437A User Manual page 83

20 msample/second adc with filters and fifo

Table of Contents

E1437A User's Guide

VXI plug&play Programming Reference

hpe1437_input_autozero

Nulls out the input DC offset voltage

VXIplug&play Syntax

#include "hpe1437.h"

ViStatus hpe1437_input_autozero(ViSession id);

Description

hpe1437_input_autozero updates a table of DC offset corrections to be used with

each input setup condition. The applicable correction from this table is automatically

added to the input offset parameter to achieve the correct DC offset value. Because of

the length of time needed to execute this function, it is not automatically called when

the module is reset. Thus, the user program is responsible for explicitly initiating the

autozero. This function should be called at least once after the temperature of the

module has stabilized. The interval between calls after that depends on the importance

of DC accuracy in the user application. It is not necessary to call the autozero function

for every change of input setup parameters since the correction table maintains values

for all setup conditions.

NOTE

Calling hpe1437_input_autozero aborts any measurement already in progress

and eliminates LO phase coherence and filter synchronization in a synchronous

multi-module system. See the hpe1437_frequency_sync and

hpe1437_frequency_sync functions for details on how to re-establish LO phase

coherence and filter synchronization.

Parameters

id is the VXI instrument session pointer returned by the hpe1437_init function.

Effect on Active

This command aborts any measurement in progress.

Measurement