.TH E1432_SET_FILTER_FREQ 3 E1432
.SH NAME
.nf
e1432_set_filter_freq \- Set filter frequency of E1432 channels
e1432_get_filter_freq \- Get filter frequency of E1432 channels
.fi
.IX e1432_set_filter_freq(3) 3
.IX e1432_get_filter_freq(3) 3
.SH SYNOPSIS
.cS
SHORTSIZ16 e1432_set_filter_freq(E1432ID hw, SHORTSIZ16 ID,
                                 FLOATSIZ32 filter_freq)
SHORTSIZ16 e1432_get_filter_freq(E1432ID hw, SHORTSIZ16 ID,
                                 FLOATSIZ32 *filter_freq)
.cE
.SH DESCRIPTION
\fIe1432_set_filter_freq\fR sets the filter frequency, of a single
channel or group of channels \fIID\fR, to the value given in
\fIfilter_freq\fR.  Normally this is the cutoff frequency of the
analog filter on the output of a source, or the cutoff frequency of an
input filter on a charge input.

\fIe1432_get_filter_freq\fR returns the current value of the filter
frequency, of a single channel or group of channels \fIID\fR, into a
memory location pointed to by \fIfilter_freq\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.

\fIfilter_freq\fR is the filter frequency in Hertz.

For input channels, filter frequency is not generally used.  Most
input channels have a fixed analog filter that can't be adjusted.
However, the Charge Break-out Box has a 2 kHz input filter available
on the charge input.  This function can be used to switch this 2 kHz
filter in and out.

For source channels, the filter frequency generally specifies the
cutoff frequency of the analog filter at the output of the source.
For the Option 1D4 single-channel source board, this function can be
used to switched between a 6.4 kHz and a 25.6 kHz output filter.

For tach channels, filter frequency is not generally used.
.SH "RESET VALUE"
After a reset, the \fIfilter_freq\fR is set to the minimum valid
filter frequency for each channel, except source channels which are set
to 25.6 kHz.
.SH "RETURN VALUE"
Return 0 if successful, a (negative) error number otherwise.
.SH "SEE ALSO"
.na
e1432_get_filter_freq_limits, e1432_bob
.ad
