.TH E1432_SET_COUPLING_FREQ 3 E1432
.SH NAME
.nf
e1432_set_coupling_freq \- Set AC coupling frequency
e1432_get_coupling_freq \- Get current AC coupling frequency
.fi
.IX e1432_set_coupling_freq(3) 3
.IX e1432_get_coupling_freq(3) 3
.SH SYNOPSIS
.cS
SHORTSIZ16 e1432_set_coupling_freq(E1432ID hw, SHORTSIZ16 ID,
                                   FLOATSIZ32 coupling_freq)
SHORTSIZ16 e1432_get_coupling_freq(E1432ID hw, SHORTSIZ16 ID,
                                   FLOATSIZ32 *coupling_freq)
.cE
.SH DESCRIPTION
\fIe1432_set_coupling_freq\fR sets the AC coupling frequency, of a
single channel or group of channels \fIID\fR, to the value given in
\fIcoupling_freq\fR.

\fIe1432_get_coupling_freq\fR returns the current value of the AC
coupling frequency, of a single channel or group of channels \fIID\fR,
into a memory location pointed to by \fIcoupling_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.

\fIcoupling_freq\fR is the desired AC coupling frequency in Hz.  This
frequency is the 3 dB point of the high-pass filter that implements AC
coupling.

The AC coupling frequency is used only for input channels - source and
tach channels do not have AC coupling filters.

The AC coupling frequency is only controllable on E1433 196 kHz input
channels.  E1432 51.2 kHz input channels have a fixed AC coupling
filter at roughly 1 Hz.  Any attempt to set the AC coupling frequency
of an E1432 input channel will generate an error.  However,
\fIe1432_get_coupling_freq\fR will return 1.0 for E1432 input
channels.

The AC coupling frequency is used only when an input channel is AC
coupled (see \fIe1432_set_coupling\fR).  The AC coupling frequency is
settable over a continuous range of 0.1 Hz to 100 Hz.
.SH "RESET VALUE"
After a reset, input channels have the \fIcoupling_freq\fR set to 1 Hz.
.SH "RETURN VALUE"
Return 0 if successful, a (negative) error number otherwise.
.SH "SEE ALSO"
.na
e1432_get_coupling_freq_limits, e1432_set_coupling
.ad
