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Diffstat (limited to 'Documentation/DocBook/media/dvb/fe-set-voltage.xml')
-rw-r--r-- | Documentation/DocBook/media/dvb/fe-set-voltage.xml | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/dvb/fe-set-voltage.xml b/Documentation/DocBook/media/dvb/fe-set-voltage.xml new file mode 100644 index 000000000..c89a6f79b --- /dev/null +++ b/Documentation/DocBook/media/dvb/fe-set-voltage.xml @@ -0,0 +1,69 @@ +<refentry id="FE_SET_VOLTAGE"> + <refmeta> + <refentrytitle>ioctl FE_SET_VOLTAGE</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>FE_SET_VOLTAGE</refname> + <refpurpose>Allow setting the DC level sent to the antenna subsystem.</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_voltage *<parameter>voltage</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_VOLTAGE</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>voltage</parameter></term> + <listitem> + <para>pointer to &fe-sec-voltage;</para> + <para>Valid values are described at &fe-sec-voltage;.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + +<para>This ioctl allows to set the DC voltage level sent through the antenna + cable to 13V, 18V or off.</para> +<para>Usually, a satellite antenna subsystems require that the digital TV + device to send a DC voltage to feed power to the LNBf. Depending on the + LNBf type, the polarization or the intermediate frequency (IF) of the LNBf + can controlled by the voltage level. Other devices (for example, the ones + that implement DISEqC and multipoint LNBf's don't need to control the + voltage level, provided that either 13V or 18V is sent to power up the + LNBf.</para> +<para>NOTE: if more than one device is connected to the same antenna, + setting a voltage level may interfere on other devices, as they may lose + the capability of setting polarization or IF. So, on those + cases, setting the voltage to SEC_VOLTAGE_OFF while the device is not is + used is recommended.</para> + +&return-value-dvb; +</refsect1> + +</refentry> |