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TONE_DETECT()

Synopsis

Asynchronously detects a tone

Description

The TONE_DETECT function detects a single-frequency tone and keeps track of how many times the tone has been detected.

When reading this function (instead of writing), supply 'tx' to get the number of times a tone has been detected in the TX direction and 'rx' to get the number of times a tone has been detected in the RX direction.

Example: intercept2600
same => n,Set(TONE_DETECT(2600,1000,g(got-2600,s,1))=) ; detect 2600 Hz
same => n,Wait(15)
same => n,NoOp(${TONE_DETECT(rx)})
Example: dropondialtone
same => n,Set(TONE_DETECT(0,,bg(my-hangup,s,1))=) ; disconnect a call if we hear a busy signal
same => n,Goto(somewhere-else)
same => n(myhangup),Hangup()
Example: removedetector
same => n,Set(TONE_DETECT(0,,x)=) ; remove the detector from the channel

Syntax

TONE_DETECT(freq[,duration_ms,options])
Arguments

  • freq - Frequency of the tone to detect. To disable frequency detection completely (e.g. for signal detection only), specify 0 for the frequency.

  • duration_ms - Minimum duration of tone, in ms. Default is 500ms. Using a minimum duration under 50ms is unlikely to produce accurate results.

  • options

    • a - Match immediately on Special Information Tones, instead of or in addition to a particular frequency.

    • b - Match immediately on a busy signal, instead of or in addition to a particular frequency.

    • c - Match immediately on a dial tone, instead of or in addition to a particular frequency.

    • d - Custom decibel threshold to use. Default is 16.

    • g - Go to the specified context,exten,priority if tone is received on this channel. Detection will not end automatically.

    • h - Go to the specified context,exten,priority if tone is transmitted on this channel. Detection will not end automatically.

    • n - Number of times the tone should be detected (subject to the provided timeout) before going to the destination provided in the 'g' or 'h' option. Default is 1.

    • p - Match immediately on audible ringback tone, instead of or in addition to a particular frequency.

    • r - Apply to received frames only. Default is both directions.

    • s - Squelch tone.

    • t - Apply to transmitted frames only. Default is both directions.

    • x - Destroy the detector (stop detection).

Generated Version

This documentation was generated from Asterisk branch 21 using version GIT