Documentation/DocBook/media/dvb/fe-set-tone.xml

<refentry id="FE_SET_TONE">
  <refmeta>
    <refentrytitle>ioctl FE_SET_TONE</refentrytitle>
    &manvol;
  </refmeta>

  <refnamediv>
    <refname>FE_SET_TONE</refname>
    <refpurpose>Sets/resets the generation of the continuous 22kHz tone.</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <funcsynopsis>
      <funcprototype>
	<funcdef>int <function>ioctl</function></funcdef>
	<paramdef>int <parameter>fd</parameter></paramdef>
	<paramdef>int <parameter>request</parameter></paramdef>
	<paramdef>enum fe_sec_tone_mode *<parameter>tone</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Arguments</title>
        <variablelist>
      <varlistentry>
	<term><parameter>fd</parameter></term>
	<listitem>
	  <para>&fe_fd;</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>request</parameter></term>
	<listitem>
	  <para>FE_SET_TONE</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><parameter>tone</parameter></term>
	<listitem>
	  <para>pointer to &fe-sec-tone-mode;</para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Description</title>

<para>This ioctl is used to set the generation of the continuous 22kHz tone.
    This call requires read/write permissions.</para>
<para>Usually, satellite antenna subsystems require that the digital TV
    device to send a 22kHz tone in order to select between high/low band on
    some dual-band LNBf. It is also used to send signals to DiSEqC equipment,
    but this is done using the DiSEqC ioctls.</para>
<para>NOTE: if more than one device is connected to the same antenna,
    setting a tone may interfere on other devices, as they may lose
    the capability of selecting the band. So, it is recommended that
    applications would change to SEC_TONE_OFF when the device is not used.</para>

&return-value-dvb;
</refsect1>

<refsect1 id="fe-sec-tone-mode-t">
<title>enum fe_sec_tone_mode</title>

<table pgwide="1" frame="none" id="fe-sec-tone-mode">
    <title>enum fe_sec_tone_mode</title>
    <tgroup cols="2">
	&cs-def;
	<thead>
	<row>
	    <entry>ID</entry>
	    <entry>Description</entry>
	</row>
	</thead>
	<tbody valign="top">
	<row>
	    <entry align="char" id="SEC-TONE-ON"><constant>SEC_TONE_ON</constant></entry>
	    <entry align="char">Sends a 22kHz tone burst to the antenna</entry>
	</row><row>
	    <entry align="char" id="SEC-TONE-OFF"><constant>SEC_TONE_OFF</constant></entry>
	    <entry align="char">Don't send a 22kHz tone to the antenna
		(except if the FE_DISEQC_* ioctls are called)</entry>
	</row>
        </tbody>
    </tgroup>
</table>
</refsect1>

</refentry>