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.. -*- coding: utf-8; mode: rst -*-
.. _FE_SET_TONE:
*****************
ioctl FE_SET_TONE
*****************
*man FE_SET_TONE(2)*
Sets/resets the generation of the continuous 22kHz tone.
Synopsis
========
.. c:function:: int ioctl( int fd, int request, enum fe_sec_tone_mode *tone )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <frontend_f_open>`.
``request``
FE_SET_TONE
``tone``
pointer to enum :ref:`fe_sec_tone_mode <fe-sec-tone-mode>`
Description
===========
This ioctl is used to set the generation of the continuous 22kHz tone.
This call requires read/write permissions.
Usually, satellite antenna subsystems require that the digital TV device
to send a 22kHz tone in order to select between high/low band on some
dual-band LNBf. It is also used to send signals to DiSEqC equipment, but
this is done using the DiSEqC ioctls.
NOTE: if more than one device is connected to the same antenna, setting
a tone may interfere on other devices, as they may lose the capability
of selecting the band. So, it is recommended that applications would
change to SEC_TONE_OFF when the device is not used.
RETURN VALUE
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
.. _fe-sec-tone-mode-t:
enum fe_sec_tone_mode
=====================
.. _fe-sec-tone-mode:
.. flat-table:: enum fe_sec_tone_mode
:header-rows: 1
:stub-columns: 0
- .. row 1
- ID
- Description
- .. row 2
- .. _`SEC-TONE-ON`:
``SEC_TONE_ON``
- Sends a 22kHz tone burst to the antenna
- .. row 3
- .. _`SEC-TONE-OFF`:
``SEC_TONE_OFF``
- Don't send a 22kHz tone to the antenna (except if the
FE_DISEQC_* ioctls are called)
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
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