.TH E1432_SET_DECIMATION_BANDWIDTH 3 E1432
.SH NAME
.nf
e1432_set_decimation_bandwidth \- Set data decimation bandwidth
e1432_get_decimation_bandwidth \- Get current data decimation bandwidth
.fi
.IX e1432_set_decimation_bandwidth(3) 3
.IX e1432_get_decimation_bandwidth(3) 3
.SH SYNOPSIS
.cS
SHORTSIZ16 e1432_set_decimation_bandwidth(E1432ID hw, SHORTSIZ16 ID,
                                          SHORTSIZ16 decBw)
SHORTSIZ16 e1432_get_decimation_bandwidth(E1432ID hw, SHORTSIZ16 ID,
                                          SHORTSIZ16 *decBw)
.cE
.SH DESCRIPTION
This function is provided only for backward compatibility with the
E1431 Host Interface library.  All new code should use
\fIe1432_set_span\fR instead.

\fIe1432_set_decimation_bandwidth\fR sets the decimation bandwidth, of
a single channel or group of channels \fIID\fR, to the value given in
\fIdecBw\fR.  The span is derived from the decimation bandwidth, and
sample clock (Fs) as follows: span = Fs / (2.56 * 2\fI**decBw\fR).

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.

\fIe1432_get_decimation_bandwidth\fR returns the current value of the
decimation bandwidth, of a single channel or group of channels \fIID\fR,
into a memory location pointed to by \fIdecBw\fR.

\fIhw\fR must be the result of a successful call to
\fIe1432_assign_channel_numbers\fR, and specifies the group of
hardware to talk to.

\fIID\fR is either the ID of a group of channels that was obtained with a
call to \fIe1432_create_channel_group\fR, or the ID of a single channel.

\fIdecBw\fR selects the bandwidth of the filter and the amount of
decimation applied to the signal.  The possible values for this
parameter range from \fB0\fR to \fB9\fR.  This parameter may also be
set with \fIe1432_set_decimation_filter\fR.
.SH "RESET VALUE"
After a reset, \fIdecBw\fR is set to \fB0\fR, therefore leading to a
full span of FS/2.56
.SH "RETURN VALUE"
Return 0 if successful, a (negative) error number otherwise.
.SH "SEE ALSO"
.na
e1432_set_span, e1432_set_decimation_filter
.ad
