<!--This file is autogenerated.  Do not edit-->
<section id="functionreference">
  <title>
    Comedi Function Reference
  </title>
<refentry id="func-ref-comedi-close">

  <refmeta>
    <refentrytitle>comedi_close</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_close</refname>
    <refpurpose>close a Comedi device</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_close</function></funcdef>
        <paramdef>comedi * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Close a device previously opened by comedi_open().
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
If sucessful, comedi_close returns 0.  On failure, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-open">

  <refmeta>
    <refentrytitle>comedi_open</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_open</refname>
    <refpurpose>open a Comedi device</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>comedi_t * <function>comedi_open</function></funcdef>
        <paramdef>const char * <parameter>filename</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Open a Comedi device specified by the file filename.
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
If sucessful, comedi_open returns a pointer to a valid comedi_t
structure.  This structure is transparent; the pointer should not
be dereferenced by the application.  NULL is returned on failure.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-loglevel">

  <refmeta>
    <refentrytitle>comedi_loglevel</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_loglevel</refname>
    <refpurpose>change Comedilib logging properties</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_loglevel</function></funcdef>
        <paramdef>int <parameter>loglevel</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function affects the output of debugging and error messages
from Comedilib.  By increasing the loglevel, additional debugging
information will be printed.  Error and debugging messages are
printed to the stream stderr.
</para><para>
The default loglevel can be set by using the environment variable
COMEDI_LOGLEVEL.  The default loglevel is 1.
</para><para>
In order to conserve resources, some debugging information is
disabled by default when Comedilib is compiled.
</para><para>
The meaning of the loglevels is as follows:
</para><para>
COMEDI_LOGLEVEL=0  Comedilib prints nothing.
</para><para>
COMEDI_LOGLEVEL=1  (default) Comedilib prints error messages when
there is a self-consistency error (i.e., an internal bug.)
</para><para>
COMEDI_LOGLEVEL=2  Comedilib prints an error message when an invalid
parameter is passed.
</para><para>
COMEDI_LOGLEVEL=3  Comedilib prints an error message whenever an
error is generated in the Comedilib library or in the C library,
when called by Comedilib.
</para><para>
COMEDI_LOGLEVEL=4  Comedilib prints a lot of junk.
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
This function returns the previous loglevel.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-perror">

  <refmeta>
    <refentrytitle>comedi_perror</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_perror</refname>
    <refpurpose>print a Comedilib error message</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>void <function>comedi_perror</function></funcdef>
        <paramdef>const char * <parameter>s</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
When a Comedilib function fails, it usually returns -1 or
NULL, depending on the return type.  An internal library
variable stores an error number, which can be retrieved with
comedi_errno().  This error number can be converted to a
human-readable form by the functions comedi_perror()
and comedi_strerror().
</para><para>
These functions are intended to mimic the behavior of the
standard C library functions perror(), strerror(), and errno.
In particular, Comedilib functions sometimes return an error
that is generated inside the C library; the comedi error
message in this case is the same as the C library.
</para><para>
The function comedi_perror() prints an error message to stderr.
The error message consists of the argument string, a colon, a
space, a description of the error condition, and a new line.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-strerror">

  <refmeta>
    <refentrytitle>comedi_strerror</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_strerror</refname>
    <refpurpose>return string describing Comedilib error code</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>char * <function>comedi_strerror</function></funcdef>
        <paramdef>int <parameter>errnum</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
When a Comedilib function fails, it usually returns -1 or
NULL, depending on the return type.  An internal library
variable stores an error number, which can be retrieved with
comedi_errno().  This error number can be converted to a
human-readable form by the functions comedi_perror()
and comedi_strerror().
</para><para>
These functions are intended to mimic the behavior of the
standard C library functions perror(), strerror(), and errno.
In particular, Comedilib functions sometimes return an error
that is generated inside the C library; the comedi error
message in this case is the same as the C library.
</para><para>
The function comedi_strerror() returns a pointer to a
character string
describing the Comedilib error errnum.  The persistence
of the returned pointer is undefined, and should not be trusted
after the next Comedilib call.  An unrecognized error number will
return a pointer to the string "undefined error", or similar.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-errno">

  <refmeta>
    <refentrytitle>comedi_errno</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_errno</refname>
    <refpurpose>number of last Comedilib error</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_errno</function></funcdef>
        <paramdef>void <parameter></parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
When a Comedilib function fails, it usually returns -1 or
NULL, depending on the return type.  An internal library
variable stores an error number, which can be retrieved with
comedi_errno().  This error number can be converted to a
human-readable form by the functions comedi_perror()
and comedi_strerror().
</para><para>
These functions are intended to mimic the behavior of the
standard C library functions perror(), strerror(), and errno.
In particular, Comedilib functions sometimes return an error
that is generated inside the C library; the comedi error
message in this case is the same as the C library.
</para><para>
The function comedi_errno() returns an integer describing
the most recent comedilib error.  This integer may be used
as the errnum parameter for comedi_strerror().
</para><para>
Note that comedi_errno() is deliberately different than the
variable errno.  This is to overcome difficulties in making
errno thread-safe.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-fileno">

  <refmeta>
    <refentrytitle>comedi_fileno</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_fileno</refname>
    <refpurpose>integer descriptor of Comedilib device</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_fileno</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_fileno returns the integer descriptor for
the device dev.  This descriptor can then be used as the
file descriptor parameter of read(), write(), etc.
This function is intended to mimic the standard C library
function fileno().  If dev is an invalid comedi_t
pointer, the function returns -1 and sets the appropriate
Comedilib error value.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-n-subdevices">

  <refmeta>
    <refentrytitle>comedi_get_n_subdevices</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_n_subdevices</refname>
    <refpurpose>number of subdevices </refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_n_subdevices</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Returns the number of subdevices belonging to the Comedi
device referenced by the parameter device.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-version-code">

  <refmeta>
    <refentrytitle>comedi_get_version_code</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_version_code</refname>
    <refpurpose>Comedi version code</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_version_code</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Returns the Comedi kernel module version code.  A valid Comedi
device referenced by the parameter device is necessary to
communicate with the kernel module.  On error, -1 is returned.
</para><para>
The version code is encoded as a bitfield of three 8-bit
numbers.  For example, 0x00073d is the version code for
version 0.7.61.
</para><para>
This function is of limited usefulness.  A typical
mis-application of this function is to use it to determine
if a certain feature is supported.  If the application needs
to know of the existence of a particular feature, an existence
test function should be written and put in the Comedilib source.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-driver-name">

  <refmeta>
    <refentrytitle>comedi_get_driver_name</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_driver_name</refname>
    <refpurpose>Comedi driver name</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>char * <function>comedi_get_driver_name</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_driver_name returns a pointer
to a string containing the name of the driver being used by comedi
for the comedi device represented by device.  This pointer is
valid until the device is closed.  This function returns NULL
if there is an error.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-board-name">

  <refmeta>
    <refentrytitle>comedi_get_board_name</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_board_name</refname>
    <refpurpose>Comedi device name</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>char * <function>comedi_get_board_name</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_board_name returns a pointer
to a string containing the name of the device.  This pointer is
valid until the comedi descriptor it is closed.  This
function returns NULL if there is an error.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-subdevice-type">

  <refmeta>
    <refentrytitle>comedi_get_subdevice_type</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_subdevice_type</refname>
    <refpurpose>type of subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_subdevice_type</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_subdevice_type() returns an
integer describing the type of subdevice that belongs to the comedi
device device and has the index subdevice.  The
function returns -1 if there is an error.

XXX Subdevice type table
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-find-subdevice-by-type">

  <refmeta>
    <refentrytitle>comedi_find_subdevice_by_type</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_find_subdevice_by_type</refname>
    <refpurpose>search for subdevice type</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_find_subdevice_by_type</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>int <parameter>type</parameter></paramdef>
        <paramdef>unsigned int <parameter>start_subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_find_subdevice_by_type() tries to
locate a subdevice belonging to comedi device device,
having type type, starting with the subdevice
start_subdevice.  If it finds a subdevice with the requested
type, it returns its index.  If it does not locate the requested
subdevice, it returns -1 and sets the Comedilib error number to
XXX "subdevice not found".  If there is an error, the function
returns -1 and sets the appropriate error.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-read-subdevice">

  <refmeta>
    <refentrytitle>comedi_get_read_subdevice</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_read_subdevice</refname>
    <refpurpose>find streaming input subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_read_subdevice</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_read_subdevice() returns the subdevice
that allows streaming input for device dev.  If no subdevice
supports streaming input, -1 is returned and the Comedilib error
number is set to XXX "subdevice not found".
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-write-subdevice">

  <refmeta>
    <refentrytitle>comedi_get_write_subdevice</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_write_subdevice</refname>
    <refpurpose>find streaming output subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_write_subdevice</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_write_subdevice() returns the subdevice
that allows streaming output for device dev.  If no subdevice
supports streaming output, -1 is returned and the Comedilib error
number is set to XXX "subdevice not found".
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-subdevice-flags">

  <refmeta>
    <refentrytitle>comedi_get_subdevice_flags</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_subdevice_flags</refname>
    <refpurpose>properties of subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_subdevice_flags</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function returns a bitfield describing the capabilities of
the specified subdevice.  If there is an error, -1 is returned,
and the Comedilib error value is set.
</para><para>
XXX table.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-n-channels">

  <refmeta>
    <refentrytitle>comedi_get_n_channels</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_n_channels</refname>
    <refpurpose>number of subdevice channels</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_n_channels</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_n_channels() returns the number
of channels of the subdevice belonging to the comedi device device
and having index subdevice.  This function returns -1 on error and
the Comedilib error value is set.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-range-is-chan-specific">

  <refmeta>
    <refentrytitle>comedi_range_is_chan_specific</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_range_is_chan_specific</refname>
    <refpurpose>range information depends on channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_range_is_chan_specific</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
If each channel of the specified subdevice has different range
information, this function returns 1.  Otherwise, this function
returns 0.  On error, this function returns -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-maxdata-is-chan-specific">

  <refmeta>
    <refentrytitle>comedi_maxdata_is_chan_specific</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_maxdata_is_chan_specific</refname>
    <refpurpose>maximum sample depends on channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_maxdata_is_chan_specific</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
If each channel of the specified subdevice has different maximum
sample values, this function returns 1.  Otherwise, this function
returns 0.  On error, this function returns -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-maxdata">

  <refmeta>
    <refentrytitle>comedi_get_maxdata</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_maxdata</refname>
    <refpurpose>maximum sample of channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>lsampl_t <function>comedi_get_maxdata</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_maxdata() returns the maximum
valid data value for channel chan of subdevice
subdevice belonging to the comedi device device
This function returns 0 on error.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-n-ranges">

  <refmeta>
    <refentrytitle>comedi_get_n_ranges</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_n_ranges</refname>
    <refpurpose>number of ranges of channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_n_ranges</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_n_ranges() returns the number
of ranges of the channel chan belonging to the subdevice
of the comedi device device.  This function returns -1 on error.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-range">

  <refmeta>
    <refentrytitle>comedi_get_range</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_range</refname>
    <refpurpose>range information of channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>comedi_range * <function>comedi_get_range</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_range() returns a pointer to a
comedi_range structure that contains information that can be used to
convert sample values to or from physical units.  The pointer is valid
until the Comedi device device is closed.  If there is an
error, NULL is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-find-range">

  <refmeta>
    <refentrytitle>comedi_find_range</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_find_range</refname>
    <refpurpose>search for range</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_find_range</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>unit</parameter></paramdef>
        <paramdef>double <parameter>min</parameter></paramdef>
        <paramdef>double <parameter>max</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_find_range() tries to
locate the optimal (smallest) range for the channel chan
belonging to a subdevice of the comedi device device,
that includes both min and max in units.
If a matching range is found, the index of the matching range is
returned.  If no matching range is available, the function returns
-1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-buffer-size">

  <refmeta>
    <refentrytitle>comedi_get_buffer_size</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_buffer_size</refname>
    <refpurpose>streaming buffer size of subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_buffer_size</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_buffer_size() returns the size (in bytes)
of the streaming buffer for the subdevice specified by device and
subdevice.  On error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-max-buffer-size">

  <refmeta>
    <refentrytitle>comedi_get_max_buffer_size</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_max_buffer_size</refname>
    <refpurpose>maximum streaming buffer size</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_max_buffer_size</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_max_buffer_size() returns the maximum
allowable size (in bytes) of the streaming buffer for the subdevice
specified by device and subdevice.  Changing the maximum buffer
size requires appropriate privileges.  On error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-set-buffer-size">

  <refmeta>
    <refentrytitle>comedi_set_buffer_size</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_set_buffer_size</refname>
    <refpurpose>streaming buffer size of subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_set_buffer_size</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>size</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_set_buffer_size() changes the size of the
streaming buffer for the subdevice specified by device and subdevice.
The parameter size must be a multiple of the virtual memory page
size.
</para><para>
The virtual memory page size can be determined using
sysconf(_SC_PAGE_SIZE).
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-trigger">

  <refmeta>
    <refentrytitle>comedi_trigger</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_trigger</refname>
    <refpurpose>perform streaming input/output (deprecated)</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_trigger</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>comedi_trig * <parameter>trig</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  deprecated
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_trigger() instructs Comedi to
perform the command specified by the trigger structure trig.
The return value depends on
the particular trig being issued.  If there is an
error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-do-insnlist">

  <refmeta>
    <refentrytitle>comedi_do_insnlist</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_do_insnlist</refname>
    <refpurpose>perform multiple instructions</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_do_insnlist</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>comedi_insnlist * <parameter>list</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_do_insnlist() performs multiple Comedi
instructions as part of one system call.  In addition, Comedi
attempts to perform the instructions atomically, that is, on
standard Linux kernels, no process preemption should occur
during the instructions.  However, the process may be preempted
before or after the group of instructions.
</para><para>
This function can be used to avoid the overhead of multiple
system calls, or to ensure that multiple instructions occur
without significant delay between them.

Preemption may occur if any of the instructions or the data
arrays of any of the instructions exist in non-resident or
copy-on-write pages.
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
The function comedi_do_insnlist() returns the number of
sucessfully completed instructions.  Error information for
the unsucessful instruction is not available.  If there is
an error before the first instruction can be executed, -1
is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-do-insn">

  <refmeta>
    <refentrytitle>comedi_do_insn</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_do_insn</refname>
    <refpurpose>perform instruction</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_do_insn</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>comedi_insn * <parameter>instruction</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_do_insn() performs a single instruction.
If sucessful, comedi_do_insn() returns the number of samples
measured, which may be less than the number of requested
samples.  Comedi limits the number of requested samples in
order to enforce fairness among processes.  If there is an
error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-lock">

  <refmeta>
    <refentrytitle>comedi_lock</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_lock</refname>
    <refpurpose>subdevice reservation</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_lock</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_lock() reserves a subdevice for use by the
current process.  While the lock is held, no other process is
allowed to read, write, or configure that subdevice, although
other processes can read information about the subdevice.  The
lock is released when comedi_unlock() is called, or the device
is closed.  If sucessful, 0 is returned.  If there is an error,
-1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-unlock">

  <refmeta>
    <refentrytitle>comedi_unlock</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_unlock</refname>
    <refpurpose>subdevice reservation</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_unlock</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_unlock() released a subdevice lock acquired
by comedi_lock().  If sucessful, 0 is returned, otherwise -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-to-phys">

  <refmeta>
    <refentrytitle>comedi_to_phys</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_to_phys</refname>
    <refpurpose>convert sample to physical units</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>double <function>comedi_to_phys</function></funcdef>
        <paramdef>lsampl_t <parameter>data</parameter></paramdef>
        <paramdef>comedi_range * <parameter>range</parameter></paramdef>
        <paramdef>lsampl_t <parameter>maxdata</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Converts data given in sample values (lsampl_t, between 0 and
maxdata) into physical units (double).  The parameter range
represents the conversion information to use, and the parameter
maxdata represents the maximum possible data value for the
channel that the data was read.
</para><para>
Conversion of endpoint sample values, that is, sample values
equal to 0 or maxdata, is affected by the Comedilib out-of-range
behavior.  If the out-of-range behavior is set to COMEDI_OOR_NAN, 
endpoint values are converted to NAN.  If the out-of-range
behavior is set to COMEDI_OOR_NUMBER, the endpoint values are
converted similarly to other values.
</para><para>
If there is an error, NAN is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-from-phys">

  <refmeta>
    <refentrytitle>comedi_from_phys</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_from_phys</refname>
    <refpurpose>convert physical units to sample</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>lsampl_t <function>comedi_from_phys</function></funcdef>
        <paramdef>double <parameter>data</parameter></paramdef>
        <paramdef>comedi_range * <parameter>range</parameter></paramdef>
        <paramdef>lsampl_t <parameter>maxdata</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Converts data given in physical units (data) into sample values
(lsampl_t, between 0 and maxdata).  The parameter rng
represents the conversion information to use, and the parameter
maxdata represents the maximum possible data value for the
channel that the data will be written to.
</para><para>
Conversion is not affected by out-of-range behavior.  Out-of-range
data parameters are silently truncated to the range 0 to maxdata.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-data-read">

  <refmeta>
    <refentrytitle>comedi_data_read</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_data_read</refname>
    <refpurpose>read single sample from channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_data_read</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
        <paramdef>lsampl_t * <parameter>data</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Reads a single sample on the channel specified by the Comedi
device device, the subdevice subdevice, and the channel channel.
For the A/D conversion (if appropriate),
the device is configured to use range specification
range and (if appropriate) analog reference type
aref. Analog reference types that are not supported
by the device are silently ignored.
</para><para>
The function comedi_data_read() reads one data value from
the specified channel and places the data value in the
location pointed to by data.
</para><para>
WARNING: comedi_data_read() does not do any pausing to
allow multiplexed analog inputs to settle before
performing an analog to digital conversion.  If you are
switching between different channels and need to allow
your analog input to settle for an accurate reading,
use comedi_data_read_delayed(), or set the
input channel at an earlier time with
comedi_data_read_hint().
</para><para>
On sucess, comedi_data_read() returns 1 (the number of samples
read).  If there is an error, -1 is returned.
</para><para>
Data values returned by this function are unsigned integers
less than or equal to the maximum sample value of the channel,
which can be determined using the function comedi_get_maxdata().
Conversion of data values to physical units can be performed
by the function comedi_to_phys().
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-data-read-delayed">

  <refmeta>
    <refentrytitle>comedi_data_read_delayed</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_data_read_delayed</refname>
    <refpurpose>read single sample from channel after delaying for specified settling time</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_data_read_delayed</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
        <paramdef>lsampl_t * <parameter>data</parameter></paramdef>
        <paramdef>unsigned int <parameter>nanosec</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Similar to comedi_data_read() except it will wait for the
specified number of nanoseconds between setting the input
channel and taking a sample.  For analog inputs, most
boards have a single
analog to digital converter which is multiplexed to be
able to read multiple channels.  If the input is not allowed
to settle after the multiplexer switches channels, the
reading will be inaccurate.  This function is useful
for allowing a multiplexed analog input to settle
when switching channels.
</para><para>
Although the settling time is specified in nanoseconds, the
actual settling time will be rounded up to the nearest
microsecond.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-data-read-hint">

  <refmeta>
    <refentrytitle>comedi_data_read_hint</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_data_read_hint</refname>
    <refpurpose>tell driver which channel/range/aref you are going to read from next</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_data_read_hint</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Used to prepare an analog input for a subsequent call to
comedi_data_read().  It is not necessary to use this
function, but it can be useful for eliminating inaccuaracies
caused by insufficient settling times when switching the
channel
or gain on an analog input.  This function sets an analog input
to the channel, range, and aref specified but does not
perform an actual analog to digital conversion.
</para><para>
Alternatively, one can simply use comedi_data_read_delayed(),
which sets up the
input, pauses to allow settling, then performs a conversion.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-data-write">

  <refmeta>
    <refentrytitle>comedi_data_write</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_data_write</refname>
    <refpurpose>write single sample to channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_data_write</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
        <paramdef>lsampl_t <parameter>data</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Writes a single sample on the channel that is specified by the
Comedi device device, the subdevice subdevice, and the channel
channel.  If appropriate, the device is configured to use range
specification range and analog reference type aref.  Analog
reference types that are not supported by the device are
silently ignored.
</para><para>
The function comedi_data_write() writes the data value specified
by the parameter data to the specified channel.
</para><para>
On sucess, comedi_data_write() returns 1 (the number of samples
written).  If there is an error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-dio-config">

  <refmeta>
    <refentrytitle>comedi_dio_config</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_dio_config</refname>
    <refpurpose>change input/output properties of channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_dio_config</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>direction</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_dio_config() configures individual channels
in a digital I/O subdevice to be either input or output, depending
on the value of parameter direction.  Valid directions are
COMEDI_INPUT or COMEDI_OUTPUT.
</para><para>
Depending on the capabilities of the hardware device, multiple
channels may be grouped together to determine direction.  In this
case, a single call to comedi_dio_config() for any channel in the
group will affect the entire group.
</para><para>
If sucessful, 1 is returned, otherwise -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-dio-read">

  <refmeta>
    <refentrytitle>comedi_dio_read</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_dio_read</refname>
    <refpurpose>read single bit from digital channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_dio_read</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int * <parameter>bit</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function reads the channel channel belonging to the
subdevice subdevice of device device.  The data value that is
read is stored in the location pointed to by bit.  This function
is equivalent to comedi_data_read(device,subdevice,channel,0,0,bit).
This function does not require a digital subdevice or a subdevice
with a maximum data value of 1 to work properly.
</para><para>
Return values and errors are the same as comedi_data_read().
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-dio-write">

  <refmeta>
    <refentrytitle>comedi_dio_write</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_dio_write</refname>
    <refpurpose>write single bit to digital channel</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_dio_write</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>bit</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function writes the value bit to the channel channel belonging
to the subdevice subdevice of device device.  This function
is equivalent to comedi_data_write(device,subdevice,channel,0,0,bit).
This function does not require a digital subdevice or a subdevice
with a maximum data value of 1 to work properly.
</para><para>
Return values and errors are the same as comedi_data_write().
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-dio-bitfield">

  <refmeta>
    <refentrytitle>comedi_dio_bitfield</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_dio_bitfield</refname>
    <refpurpose>read/write multiple digital channels</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_dio_bitfield</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>write_mask</parameter></paramdef>
        <paramdef>unsigned int * <parameter>bits</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_dio_bitfield() allows multiple channels to
be read simultaneously from a digital input or digital I/O device.
The parameter write_mask and the value pointed to by bits
are interpreted as bit fields, with the least significant bit
representing channel 0.  For each bit in write_mask that is
set to 1, the cooresponding bit in *bits is written to the digital
output channel.  After writing all the output channels, each
channel is read, and the result placed in the approprate bits in
*bits.  The result of reading an output channel is undefined.
It is not possible to access channels greater than 31 using this
function.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-sv-init">

  <refmeta>
    <refentrytitle>comedi_sv_init</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_sv_init</refname>
    <refpurpose>slowly-varying inputs</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_sv_init</function></funcdef>
        <paramdef>comedi_sv_t * <parameter>sv</parameter></paramdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  deprecated
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_sv_init() initializes the slow varying Comedi
structure sv to use the device device, the analog input subdevice
subdevice, and the channel channel.  The slow varying Comedi
structure is used by comedi_sv_measure() to accurately measure
an analog input by averaging over many samples.  The default
number of samples is 100.  This function returns 0 on success,
-1 on error.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-sv-update">

  <refmeta>
    <refentrytitle>comedi_sv_update</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_sv_update</refname>
    <refpurpose>slowly-varying inputs</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_sv_update</function></funcdef>
        <paramdef>comedi_sv_t * <parameter>sv</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  deprecated
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_sv_update() updates internal parameters of
the slowly varying Comedi structure sv.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-sv-measure">

  <refmeta>
    <refentrytitle>comedi_sv_measure</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_sv_measure</refname>
    <refpurpose>slowly-varying inputs</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_sv_measure</function></funcdef>
        <paramdef>comedi_sv_t * <parameter>sv</parameter></paramdef>
        <paramdef>double * <parameter>data</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  deprecated
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_sv_measure() uses the slowly varying Comedi
structure sv to measure a slowly varying signal.  If sucessful,
the result (in physical units) is stored in the location pointed
to by data, and the number of samples is returned.  On error, -1
is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-cmd-src-mask">

  <refmeta>
    <refentrytitle>comedi_get_cmd_src_mask</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_cmd_src_mask</refname>
    <refpurpose>streaming input/output capabilities</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_cmd_src_mask</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>comedi_cmd * <parameter>command</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The command capabilities of the subdevice indicated by the parameters
device and subdevice are probed, and the results placed in the
command structure pointed to by the parameter command.  The trigger
source elements of the command structure are set to the logical OR
value of possible trigger sources.  Other elements in the structure
are undefined.  If sucessful, 0 is returned, otherwise -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-cmd-generic-timed">

  <refmeta>
    <refentrytitle>comedi_get_cmd_generic_timed</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_cmd_generic_timed</refname>
    <refpurpose>streaming input/output capabilities</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_cmd_generic_timed</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>comedi_cmd * <parameter>command</parameter></paramdef>
        <paramdef>unsigned int <parameter>period_ns</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The command capabilities of the subdevice indicated by the parameters
device and subdevice are probed, and the results placed in the
command structure pointed to by the parameter command.  The command
structure pointed to by the parameter command is modified to be a
valid command that can be used as a parameter to comedi_command().
The command measures samples at a rate that corresponds to the
period period_ns.  The rate is adjusted to a rate that the device
can handle.  If sucessful, 0 is returned, otherwise -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-cancel">

  <refmeta>
    <refentrytitle>comedi_cancel</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_cancel</refname>
    <refpurpose>stop streaming input/output in progress</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_cancel</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_cancel() can be used to stop a Comedi command
previously started by comedi_command() that is still in progress
on the subdevice indicated by the parameters device and subdevice.
This may not return the subdevice to a ready state, since there may
be samples in the buffer that need to be read.
</para><para>
If sucessful, 0 is returned, otherwise -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-command">

  <refmeta>
    <refentrytitle>comedi_command</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_command</refname>
    <refpurpose>start streaming input/output</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_command</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>comedi_cmd * <parameter>command</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_command() starts streaming input or output.  The
command structure pointed to by the parameter command specifies the
acquisition.  The command must be able to pass comedi_command_test()
with a return value of 0, or comedi_command() will fail.
For input subdevices, sample values are read using the
function read().  For output subdevices, sample values are written
using the function write().
</para><para>
If sucessful, 0 is returned, otherwise -1.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-command-test">

  <refmeta>
    <refentrytitle>comedi_command_test</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_command_test</refname>
    <refpurpose>test streaming input/output configuration</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_command_test</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>comedi_cmd * <parameter>command</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_command_test() tests the command structure pointed
to by the parameter command and returns an integer describing the
testing stages that were sucessfully passed.  In addition, if elements
of the command structure are invalid, they may be modified.  Source
elements are modified to remove invalid source triggers.  Argument
elements are adjusted or rounded to the nearest valid value.
</para><para>
The meanings of the return value are as follows.
</para><para>
0 indicates a valid command.
</para><para>
1 indicates that one of the *_src
members of the command contained an
unsupported trigger.  The bits corresponding to the unsupported
triggers are zeroed.
</para><para>
2 indicates that the particular combination
of *_src settings is not supported by the driver, or that
one of the *_src members has the bit corresponding to
multiple trigger sources set at the same time.
</para><para>
3 indicates that one of the *_arg members
of the command is set outside the range of allowable values.
For instance, an argument for a TRIG_TIMER source which
exceeds the board's maximum speed.  The invalid *_arg
members will be adjusted to valid values.
</para><para>
4 indicates that one of the *_arg members
required adjustment.  For instance, the argument of a
TRIG_TIMER source may have been rounded to the nearest
timing period supported by the board.
</para><para>
5 indicates that some aspect of the
command's chanlist is unsupported by the board.  For example,
some board's require that all channels in the chanlist
use the same range.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-poll">

  <refmeta>
    <refentrytitle>comedi_poll</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_poll</refname>
    <refpurpose>force updating of streaming buffer</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_poll</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_poll() is used on a subdevice that has a
Comedi command in progress in order to update the streaming buffer.
If supported by the driver, all available samples are copied to
the streaming buffer.  These samples may be pending in DMA buffers
or device FIFOs.  If sucessful, the number of additional bytes
available is returned.  If there is an error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-set-max-buffer-size">

  <refmeta>
    <refentrytitle>comedi_set_max_buffer_size</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_set_max_buffer_size</refname>
    <refpurpose>streaming buffer size of subdevice</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_set_max_buffer_size</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>max_size</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_set_max_buffer_size() changes the maximum
allowable size (in bytes) of the streaming buffer for the subdevice
specified by device and subdevice.  Changing the maximum buffer
size requires appropriate privileges.  If sucessful, the old buffer
size is returned.  On error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-buffer-contents">

  <refmeta>
    <refentrytitle>comedi_get_buffer_contents</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_buffer_contents</refname>
    <refpurpose>streaming buffer status</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_buffer_contents</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_buffer_contents() is used on a subdevice
that has a Comedi command in progress.  The number of bytes that
are available in the streaming buffer is returned.  If there is
an error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-mark-buffer-read">

  <refmeta>
    <refentrytitle>comedi_mark_buffer_read</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_mark_buffer_read</refname>
    <refpurpose>streaming buffer status</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_mark_buffer_read</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>num_bytes</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_mark_buffer_read() is used on a subdevice
that has a Comedi command in progress.  This function can be
used to indicate that the next num_bytes bytes in the buffer
are no longer needed and may be discarded.
If there is an error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-buffer-offset">

  <refmeta>
    <refentrytitle>comedi_get_buffer_offset</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_buffer_offset</refname>
    <refpurpose>streaming buffer status</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_buffer_offset</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_buffer_offset() is used on a subdevice
that has a Comedi command in progress.  This function returns
the offset in bytes of the read pointer in the streaming buffer.
This offset is only useful for memory mapped buffers.
If there is an error, -1 is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-timer">

  <refmeta>
    <refentrytitle>comedi_get_timer</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_timer</refname>
    <refpurpose>timer information (deprecated)</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_get_timer</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>double <parameter>frequency</parameter></paramdef>
        <paramdef>unsigned int * <parameter>trigvar</parameter></paramdef>
        <paramdef>double * <parameter>actual_frequency</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  deprecated
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
The function comedi_get_timer converts the frequency frequency
to a number suitable to send to the driver in a comedi_trig
structure.  This function remains for compatibility with very
old versions of Comedi, that converted sampling rates to timer
values in the libary.  This conversion is now done in the kernel,
and every device has the timer type nanosec_timer, indicating
that timer values are simply a time specified in nanoseconds.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-timed-1chan">

  <refmeta>
    <refentrytitle>comedi_timed_1chan</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_timed_1chan</refname>
    <refpurpose>streaming input (deprecated)</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_timed_1chan</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
        <paramdef>double <parameter>frequency</parameter></paramdef>
        <paramdef>unsigned int <parameter>num_samples</parameter></paramdef>
        <paramdef>double * <parameter>data</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  deprecated
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
Not documented.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-set-global-oor-behavior">

  <refmeta>
    <refentrytitle>comedi_set_global_oor_behavior</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_set_global_oor_behavior</refname>
    <refpurpose>out-of-range behavior</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_set_global_oor_behavior</function></funcdef>
        <paramdef>enum comedi_oor_behavior <parameter>behavior</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  alpha
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function changes the Comedilib out-of-range behavior.
This currently affects the behavior of comedi_to_phys() when
converting endpoint sample values, that is, sample values
equal to 0 or maxdata.  If the out-of-range behavior is set to
COMEDI_OOR_NAN, endpoint values are converted to NAN.  If the
out-of-range behavior is set to COMEDI_OOR_NUMBER, the endpoint
values are converted similarly to other values.
</para><para>
The previous out-of-range behavior is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-apply-calibration">

  <refmeta>
    <refentrytitle>comedi_apply_calibration</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_apply_calibration</refname>
    <refpurpose>set calibration from file</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_apply_calibration</function></funcdef>
        <paramdef>comedi_t <parameter>*device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
        <paramdef>const char <parameter>*file_path</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  alpha
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function sets the calibration of the specified subdevice
so that it is in proper calibration when using the specified
channel, range and aref.  It does so by performing writes
to the appropriate channels of the board's calibration
subdevice(s).  Depending on the hardware, the
calibration settings used may or may not depend on the channel,
range, or aref.  Furthermore, the calibrations for different
channels, ranges, or arefs may not be independent.
For example, some boards cannot have their analog inputs calibrated
for multiple input
ranges simultaneously.  Applying a calibration for range 1 may
blow away a previously applied calibration for range 0.  Applying
a calibration for analog input channel 0 may cause the same
calibration to be applied to all the
other analog input channels as well.
Your only guarantee is that calls to comedi_apply_calibration()
on different subdevices will not interfere with each other.
</para><para>
In practice, their are some rules of thumb on how
calibrations behave.  No calibrations depend on the aref.
A multiplexed analog input will have calibration settings that
do not depend on the channel, and applying a setting for one
channel will affect
all channels equally.  Analog outputs, and analog inputs
with independent a/d converters for each input channel, will have
calibrations settings which do depend on the channel, and the
settings for each channel will be independent of the other
channels.
</para><para>
If you wish to investigate exactly what comedi_apply_calibration()
is doing, you can perform reads on your board's calibration
subdevice to see which calibration channels it is changing.
You can also try to decipher the calibration file directly (it's a
text file).
</para><para>
The file_path parameter can be used
to specify the file which contains the calibration information.
If <parameter>file_path</parameter> is NULL, then comedilib
will use a default
file location.  The calibration information used by this function
is generated by the comedi_calibrate program (see its man page).
</para><para>
The functions comedi_parse_calibration_file(),
comedi_apply_parsed_calibration(), and comedi_cleanup_calibration()
provide the same functionality at a slightly lower level.
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
Zero on success, a negative number on failure.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-apply-parsed-calibration">

  <refmeta>
    <refentrytitle>comedi_apply_parsed_calibration</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_apply_parsed_calibration</refname>
    <refpurpose>set calibration from memory</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>int <function>comedi_apply_parsed_calibration</function></funcdef>
        <paramdef>comedi_t * <parameter>device</parameter></paramdef>
        <paramdef>unsigned int <parameter>subdevice</parameter></paramdef>
        <paramdef>unsigned int <parameter>channel</parameter></paramdef>
        <paramdef>unsigned int <parameter>range</parameter></paramdef>
        <paramdef>unsigned int <parameter>aref</parameter></paramdef>
        <paramdef>const comedi_calibration_t <parameter>*calibration</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  alpha
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function is similar to comedi_apply_calibration()
except the calibration information is read from memory
instead of a file.  This function can be more
efficient than comedi_apply_calibration() since the
calibration file does not need to be reparsed with
every call.  The <parameter>calibration</parameter> is
obtained by a call to comedi_parse_calibration_file().
</para><para>
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
Zero on success, a negative number on failure.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-cleanup-calibration-file">

  <refmeta>
    <refentrytitle>comedi_cleanup_calibration_file</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_cleanup_calibration_file</refname>
    <refpurpose>free calibration resources</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>void <function>comedi_cleanup_calibration_file</function></funcdef>
        <paramdef>comedi_calibration_t <parameter>*calibration</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  alpha
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function frees the resources associated with a
<parameter>calibration</parameter> obtained from
comedi_parse_calibration_file().  <parameter>calibration</parameter>
can not be used again after calling this function.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-get-default-calibration-path">

  <refmeta>
    <refentrytitle>comedi_get_default_calibration_path</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_get_default_calibration_path</refname>
    <refpurpose>get default calibration file path</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>char* <function>comedi_get_default_calibration_path</function></funcdef>
        <paramdef>comedi_t <parameter>*dev</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  alpha
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function returns a string containing a default calibration file
path appropriate for <parameter>dev</parameter>.  Memory for the
string is allocated by the function, and should be freed when
the string is no longer needed.
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
A string which contains a file path useable by
comedi_parse_calibration_file().  On error, NULL is returned.
</para><para>
    </para>
  </refsect1>
</refentry>
<refentry id="func-ref-comedi-parse-calibration-file">

  <refmeta>
    <refentrytitle>comedi_parse_calibration_file</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>comedi_parse_calibration_file</refname>
    <refpurpose>set calibration</refpurpose>
  </refnamediv>
  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;comedilib.h&gt;</funcsynopsisinfo>
      <funcprototype>
        <funcdef>comedi_calibration_t* <function>comedi_parse_calibration_file</function></funcdef>
        <paramdef>const char <parameter>*file_path</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>
  <refsect1>
    <title>
      Status
    </title>
    <para>
	  alpha
    </para>
  </refsect1>
  <refsect1>
    <title>
      Description
    </title>
    <para>
This function parses a calibration file (produced by the
comedi_calibrate program) and returns a pointer to a
comedi_calibration_t which can be passed to the
comedi_apply_parsed_calibration() function.  When you are
finished using the comedi_calibration_t, you should
call comedi_cleanup_calibration() to free the resources
associated with the comedi_calibration_t.
</para><para>
The comedi_get_default_calibration_path() function may
be useful in conjunction with this function.
    </para>
  </refsect1>
  <refsect1>
    <title>
      Return value
    </title>
    <para>
A pointer to parsed calibration information on success,  or NULL on failure.
    </para>
  </refsect1>
</refentry>
</section>