.TH E1432_SET_FILTER_SETTLING_TIME 3 E1432
.SH NAME
.nf
e1432_set_filter_settling_time \- Change default filter settling time
e1432_get_filter_settling_time \- Get current filter settling time
.fi
.IX e1432_set_filter_settling_time(3) 3
.IX e1432_get_filter_settling_time(3) 3
.SH SYNOPSIS
.cS
SHORTSIZ16 e1432_set_filter_settling_time(E1432ID hw, SHORTSIZ16 ID,
                                          FLOATSIZ32 setlTime)
SHORTSIZ16 e1432_get_filter_settling_time(E1432ID hw, SHORTSIZ16 ID,
                                          FLOATSIZ32 *setlTime)
.cE
.SH DESCRIPTION
\fIe1432_set_filter_settling_time\fR sets the filter settling time,
of a single channel or group of channels \fIID\fR,
to the value given in \fIsetlTime\fR.

\fIe1432_get_filter_settling_time\fR returns the current value of the filter
settling time, of a single channel or group of channels \fIID\fR,
into a memory location pointed to by \fIsetlTime\fR.

This parameter is a "global" parameter.  It applies to an entire E1432
module rather than to one of its channels.  The \fIID\fR parameter is
used only to identify which module the function applies to, and all
channels in that module will report the same value for this parameter.

\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.

\fIsetlTime\fR is the time given to the filter to settle its output.
This time has an impact on the time spent in the \fBSETTLING\fR state
of the measurement loop:
The E1432 will wait for that time to elapse, before moving to the
\fBIDLE\fR state.
This parameter is given in seconds, and may be set to any value
between \fB0.0\fR seconds, and \fB10,000.0\fR seconds.

The actual settling time will be the greater of \fIsetlTime\fR and the
internally computed settling time, which accounts for ADC settling and
digital filter settling.

The two primary uses for this functionality are to handle AC coupling
settling and Octave band settling, both of which are not handled by
the internally computed settling time, due to the large times which may
be involved.

AC coupling settling for the E1432 front ends should be set to 2.2 seconds
for full protection.

Worst case AC coupling settling for the E1433 should be 5 seconds for the
slewing of the active coupling plus 2.1/\fIcoupling_freq\fR, where
\fIcoupling_freq\fR is set by the \fIe1432_set_coupling_freq\fR function.

Settling for the lowest octave band, \fIoctave_start_freq\fR, as set by
\fIe1432_set_octave_start_freq\fR, should be 7.1/\fIoctave_start_freq\fR
for full octave measurements and 21.6/\fIoctave_start_freq\fR for one
third octave measurements.
Settling in exponential Octave average mode,
as set by \fIe1432_set_octave_avg_mode\fR,
should be an additional 7 times the exponential average time constant,
as set by \fIe1432_set_octave_time_const\fR.
Allowing for settling is of particular importance to obtaining accurate
measurement results for the Octave hold modes, as set by
\fIe1432_set_octave_hold_mode\fR.

.SH "RESET VALUE"
After a reset, \fIsetlTime\fR is set to \fB0.0\fR samples.
.SH "RETURN VALUE"
Return 0 if successful, a (negative) error number otherwise.
.SH "SEE ALSO"
.na
e1432_get_filter_settling_time_limits
.ad
