2.4.10. ioctl FE_SET_TONE¶
2.4.10.1. Name¶
FE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.
2.4.10.3. Arguments¶
fd- File descriptor returned by
open(). tone- an integer enumered value described at
fe_sec_tone_mode
2.4.10.4. 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.
2.4.10.5. 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 Generic Error Codes chapter.