Download E1430A VXI ADC User`s Guide

HP E1430A User’s Guide
e1430_set_decimation_filter
e1430_set_decimation_filter
Set all decimation filter parameters
SYNOPSIS
#include "e1430.h"
SHORTSIZ16 e1430_set_decimation_filter(groupID, level, state, output, tag)
SHORTSIZ16 groupID;
SHORTSIZ16 level;
SHORTSIZ16 state;
SHORTSIZ16 output;
SHORTSIZ16 tag;
DESCRIPTION
Note:
E1430_set_decimation_filter sets all parameters associated with the decimation
filter of an HP E1430. Decimation allows data reduction on oversampled data,
saving only those points needed to reconstruct the waveform. A decimation of 2
keeps every other data point, a decimation of 4 keeps every fourth data point, etc.
The bandwidth of the data must be reduced at the same time to prevent aliasing.
Using this function while a measurement is running will force all HP E1430As in
the group into the IDLE state.
GroupID is the group ID of a single HP E1430A or group of HP E1430As that
was obtained by a call to e1430_create_module_group. Level selects the
bandwidth of the filter and the amount of decimation applied to the signal. It
sets both the bandwidth of the signal output and the magnitude triggering
circuitry to the same value. If it is desired to set these bandwidths to different
values, the e1430_set_decimation_bandwidth function can be used. If this
parameter is set to zero, all filtering except the analog anti-alias filter is
disabled.
If level is greater than 24 it will be set to 24. If the state parameter is set to
E1430_DECIMATION_ON, the maximum value of these parameters is 23. The
total decimation level can not exceed 24. If these parameters is less than zero,
the function will return the error, ERR1340_ILLEGAL_FILTER_BW.
State selects additional decimation on the output of the decimation filter.
When this parameter is set to E1430_DECIMATION_OFF all samples from the
decimation filter are saved. This results in oversampling by almost a factor of 2
at every level except zero. Using E1430_DECIMATION_ON decimates by an
extra factor of 2 in addition to the decimation level set by the level. If this
parameter is set to E1430_DECIMATION_ON when the bandwidth parameters
for either the data or triggering is set to 24, these bandwidth parameters are
reduced to 23. The total decimation level can not exceed 24. If a value other
than the these two legal values is used for state, the function will return the
error, ERR1340_ILLEGAL_DECIMATE_MODE.
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