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

   1 <refentry id="FE_SET_TONE">
   2   <refmeta>
   3     <refentrytitle>ioctl FE_SET_TONE</refentrytitle>
   4     &manvol;
   5   </refmeta>
   6
   7   <refnamediv>
   8     <refname>FE_SET_TONE</refname>
   9     <refpurpose>Sets/resets the generation of the continuous 22kHz tone.</refpurpose>
  10   </refnamediv>
  11
  12   <refsynopsisdiv>
  13     <funcsynopsis>
  14       <funcprototype>
  15         <funcdef>int <function>ioctl</function></funcdef>
  16         <paramdef>int <parameter>fd</parameter></paramdef>
  17         <paramdef>int <parameter>request</parameter></paramdef>
  18         <paramdef>&fe-sec-tone-mode; *<parameter>tone</parameter></paramdef>
  19       </funcprototype>
  20     </funcsynopsis>
  21   </refsynopsisdiv>
  22
  23   <refsect1>
  24     <title>Arguments</title>
  25         <variablelist>
  26       <varlistentry>
  27         <term><parameter>fd</parameter></term>
  28         <listitem>
  29           <para>&fe_fd;</para>
  30         </listitem>
  31       </varlistentry>
  32       <varlistentry>
  33         <term><parameter>request</parameter></term>
  34         <listitem>
  35           <para>FE_SET_TONE</para>
  36         </listitem>
  37       </varlistentry>
  38       <varlistentry>
  39         <term><parameter>pointer to &fe-sec-tone-mode;</parameter></term>
  40       </varlistentry>
  41     </variablelist>
  42   </refsect1>
  43
  44   <refsect1>
  45     <title>Description</title>
  46
  47 <para>This ioctl is used to set the generation of the continuous 22kHz tone.
  48     This call requires read/write permissions.</para>
  49 <para>Usually, satellital antenna subsystems require that the digital TV
  50     device to send a 22kHz tone in order to select between high/low band on
  51     some dual-band LNBf. It is also used to send signals to DiSEqC equipment,
  52     but this is done using the DiSEqC ioctls.</para>
  53 <para>NOTE: if more than one device is connected to the same antenna,
  54     setting a tone may interfere on other devices, as they may lose
  55     the capability of selecting the band. So, it is recommended that
  56     applications would change to SEC_TONE_OFF when the device is not used.</para>
  57
  58 &return-value-dvb;
  59 </refsect1>
  60
  61 <section id="fe-sec-tone-mode-t">
  62 <title>enum fe_sec_voltage</title>
  63
  64 <table pgwide="1" frame="none" id="fe-sec-tone-mode">
  65     <title>enum fe_sec_tone_mode</title>
  66     <tgroup cols="2">
  67         &cs-def;
  68         <thead>
  69         <row>
  70             <entry>ID</entry>
  71             <entry>Description</entry>
  72         </row>
  73         </thead>
  74         <tbody valign="top">
  75         <row>
  76             <entry align="char">SEC_TONE_ON</entry>
  77             <entry align="char">Sends a 22kHz tone burst to the antenna</entry>
  78         </row><row>
  79             <entry align="char">SEC_TONE_OFF</entry>
  80             <entry align="char">Don't send a 22kHz tone to the antenna
  81                 (except if the FE_DISEQC_* ioctls are called)</entry>
  82         </row>
  83         </tbody>
  84     </tgroup>
  85 </table>
  86 </section>
  87
  88 </refentry>