1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 .. c:namespace:: DTV.fe 2 .. c:namespace:: DTV.fe
3 3
4 .. _FE_SET_TONE: 4 .. _FE_SET_TONE:
5 5
6 ***************** 6 *****************
7 ioctl FE_SET_TONE 7 ioctl FE_SET_TONE
8 ***************** 8 *****************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 FE_SET_TONE - Sets/resets the generation of th 13 FE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: FE_SET_TONE 18 .. c:macro:: FE_SET_TONE
19 19
20 ``int ioctl(int fd, FE_SET_TONE, enum fe_sec_t 20 ``int ioctl(int fd, FE_SET_TONE, enum fe_sec_tone_mode tone)``
21 21
22 Arguments 22 Arguments
23 ========= 23 =========
24 24
25 ``fd`` 25 ``fd``
26 File descriptor returned by :c:func:`open( 26 File descriptor returned by :c:func:`open()`.
27 27
28 ``tone`` 28 ``tone``
29 an integer enumered value described at :c: 29 an integer enumered value described at :c:type:`fe_sec_tone_mode`
30 30
31 Description 31 Description
32 =========== 32 ===========
33 33
34 This ioctl is used to set the generation of th 34 This ioctl is used to set the generation of the continuous 22kHz tone.
35 This call requires read/write permissions. 35 This call requires read/write permissions.
36 36
37 Usually, satellite antenna subsystems require 37 Usually, satellite antenna subsystems require that the digital TV device
38 to send a 22kHz tone in order to select betwee 38 to send a 22kHz tone in order to select between high/low band on some
39 dual-band LNBf. It is also used to send signal 39 dual-band LNBf. It is also used to send signals to DiSEqC equipment, but
40 this is done using the DiSEqC ioctls. 40 this is done using the DiSEqC ioctls.
41 41
42 .. attention:: If more than one device is conn 42 .. attention:: If more than one device is connected to the same antenna,
43 setting a tone may interfere on other devic 43 setting a tone may interfere on other devices, as they may lose the
44 capability of selecting the band. So, it is 44 capability of selecting the band. So, it is recommended that applications
45 would change to SEC_TONE_OFF when the devic 45 would change to SEC_TONE_OFF when the device is not used.
46 46
47 Return Value 47 Return Value
48 ============ 48 ============
49 49
50 On success 0 is returned. 50 On success 0 is returned.
51 51
52 On error -1 is returned, and the ``errno`` var 52 On error -1 is returned, and the ``errno`` variable is set
53 appropriately. 53 appropriately.
54 54
55 Generic error codes are described at the 55 Generic error codes are described at the
56 :ref:`Generic Error Codes <gen-errors>` chapte 56 :ref:`Generic Error Codes <gen-errors>` chapter.
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