.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: DTV.fe

.. _FE_SET_TONE:

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ioctl FE_SET_TONE

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Name

FE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.

Synopsis

.. c:macro:: FE_SET_TONE

int ioctl(int fd, FE_SET_TONE, enum fe_sec_tone_mode tone)

Arguments

fd File descriptor returned by :c:func:open().

tone An integer enumerated value described at :c:type: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.

.. attention:: 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 is returned, and the errno variable is set appropriately.

Generic error codes are described at the :ref:Generic Error Codes <gen-errors> chapter.