| <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> |