1 .. -*- coding: utf-8; mode: rst -*-
12 FE_SET_VOLTAGE - Allow setting the DC level sent to the antenna subsystem.
18 .. c:function:: int ioctl( int fd, FE_SET_VOLTAGE, enum fe_sec_voltage voltage )
26 File descriptor returned by :ref:`open() <frontend_f_open>`.
29 an integer enumered value described at :c:type:`fe_sec_voltage`
35 This ioctl allows to set the DC voltage level sent through the antenna
36 cable to 13V, 18V or off.
38 Usually, a satellite antenna subsystems require that the digital TV
39 device to send a DC voltage to feed power to the LNBf. Depending on the
40 LNBf type, the polarization or the intermediate frequency (IF) of the
41 LNBf can controlled by the voltage level. Other devices (for example,
42 the ones that implement DISEqC and multipoint LNBf's don't need to
43 control the voltage level, provided that either 13V or 18V is sent to
46 .. attention:: if more than one device is connected to the same antenna,
47 setting a voltage level may interfere on other devices, as they may lose
48 the capability of setting polarization or IF. So, on those cases, setting
49 the voltage to SEC_VOLTAGE_OFF while the device is not is used is
56 On success 0 is returned, on error -1 and the ``errno`` variable is set
57 appropriately. The generic error codes are described at the
58 :ref:`Generic Error Codes <gen-errors>` chapter.