Callflows. Call Settings Actions. Collect DTMF

Modified on Wed, Jul 5, 2023 at 1:23 PM

Description: This is how the Collect DTMF Action works and how it can be integrated into call flows.



DTMF is an acronym for Dual-Tone Multi-Frequency, a type of signaling that is used for the transmission of digits or signals over telephone lines. 

In the context of call flows, DTMF can be used to send signals or responses during an automated call or an interactive voice response (IVR) system. When a caller presses a key on their phone, the DTMF system generates two distinct tones simultaneously, which are then decoded by the system on the other end to identify the entered digit or signal. Since each key on a phone has a unique combination of two tones, it is called "dual-tone".


When a customer calls a service center that uses an IVR system, they may hear a recorded message prompting them to use the dial pad to enter certain numeric information, such as a personal identification number, credit card number, or a specific code. 

This scenario will serve as an illustration of a call flow that we will be creating in this article.


After creating a new call flow, completing the Main Callflow Block with essential information, and assigning a Play Media Block with a message that asks a caller to enter their personal number, you can implement the Collect DTMF Action Block to the configured call flow. The Collect DTMF Block is located within the Call Settings group of Actions in the Catalog of Actions on the Callflow Configurator's right-hand side.

By using the drag-and-drop technique, you can transfer the Collect DTMF Block from the Catalog and integrate them into several places of the Callflow diagram.

When you drop the Collect DTMF Block onto the Callflow diagram, a pop-up window will appear displaying the various parameters of the Block that need to be configured. 

Five parameters need to be configured in that section:

  • Collection Name: this field allows you to customize the name of the stored DTMF collection. 
If you prefer to use the default value set by the back-end, you can leave this field blank.


  • Interdigit Timeout: this field allows you to specify the duration, measured in milliseconds, for which the system will wait for the next DTMF signal.
If you prefer to use the default value set by the back-end, you can leave this field blank.


  • Max Digits: this field enables you to set the upper limit on the number of DTMFs that the system will collect from the caller.
  • Terminator: within this field, there is a dropdown menu of primary keys, and you must select one of them to act as the DTMF that terminates the collection process before the timeout occurs.


  • Timeout: the purpose of this field is to define the duration, measured in milliseconds, for which the system should await the initial DTMF signal. The default duration for this is 5000 milliseconds.


A properly configured Collect DTMF Blocks integrated into a call flow will be displayed as follows.

Within the Block, there is no indication of all the previously set parameters.


Once changes in the Callflow diagram have been made, the "Save" button will become active, and clicking on it will open a drop-down menu with three saving options. 

  • Save Changes: by clicking this button, you will easily save all of the changes you have made. 
  • Save and Duplicate: clicking on this button will save all modifications made to the current call flow and create a new call flow that duplicates the original. The name of the duplicated call flow will include the name of the original call flow, followed by the word "copy"

The main Block of the duplicated call flow, which displays the extension and phone numbers in the original call flow, will be left blank. 

  • Save and Create: clicking on this button will save all modifications made to the current call flow and create a new empty call flow
  • Cancel: clicking on this button will cancel any modifications made to the call flow. If changes have been made, the system will prompt you to confirm the cancellation of those changes.


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