1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 .. c:namespace:: DTV.fe
13 FE_SET_VOLTAGE - Allow setting the DC level sent to the antenna subsystem.
18 .. c:macro:: FE_SET_VOLTAGE
20 ``int ioctl(int fd, FE_SET_VOLTAGE, enum fe_sec_voltage voltage)``
26 File descriptor returned by :c:func:`open()`.
29 an integer enumered value described at :c:type:`fe_sec_voltage`
34 This ioctl allows to set the DC voltage level sent through the antenna
35 cable to 13V, 18V or off.
37 Usually, a satellite antenna subsystems require that the digital TV
38 device to send a DC voltage to feed power to the LNBf. Depending on the
39 LNBf type, the polarization or the intermediate frequency (IF) of the
40 LNBf can controlled by the voltage level. Other devices (for example,
41 the ones that implement DISEqC and multipoint LNBf's don't need to
42 control the voltage level, provided that either 13V or 18V is sent to
45 .. attention:: if more than one device is connected to the same antenna,
46 setting a voltage level may interfere on other devices, as they may lose
47 the capability of setting polarization or IF. So, on those cases, setting
48 the voltage to SEC_VOLTAGE_OFF while the device is not is used is
54 On success 0 is returned.
56 On error -1 is returned, and the ``errno`` variable is set
59 Generic error codes are described at the
60 :ref:`Generic Error Codes <gen-errors>` chapter.