Collecting dual-tone multi-frequency (DTMF) digits

About the DTMF collection action

DTMF sessions begin for Voice Gateway when an action sequence is triggered in Watson Assistant, starting with the vgwActCollectDTMF action tag.

The following action tells Voice Gateway to play the defined text to the caller, and then begin a DTMF session. The session ends when the caller either presses # or a post response timeout occurs.

{
  "output": {
    "text": {
      "values": [
        "Please enter the extension you are trying to reach and then press #."
      ]
    },
    "vgwAction": {
      "command": "vgwActCollectDTMF",
      "parameters": {
        "dtmfTermKey": "#",

      }
    }
  }
}

{
  "output": {
    "text": {
      "values": [
        "Please enter the extension you are trying to reach."
      ]
    },
    "vgwAction": {
      "command": "vgwActCollectDTMF",
      "parameters": {
        "dtmfMinCount": "4",
        "dtmfMaxCount": "6",
        "dtmfIgnoreSpeech": "true",
        "dtmfInterDigitTimeoutCount":"1000"

      }
    }
  }
}

{
  "output": {
    "text": {
      "values": [
        "Please enter the extension you are trying to reach."
      ]
    },
    "vgwActionSequence": [
      {
        "command": "vgwActDisableDTMFBargeIn"
      },
      {
        "command": "vgwActPlayText"
      },
      {
        "command": "vgwActCollectDTMF",
        "parameters": {
          "dtmfMinCount": "3",
          "dtmfIgnoreSpeech": true,
          "dtmfinterDigitTimeoutCount": "1000"
        }
      }
    ]
  }
}

Using an action to collect a specified number of DTMF digits

You can use either an exact number or a range of expected inputs for your DTMF collection. To collect a specific number of digits, configure the dtmfCount attribute.

Using an action to collect a specified range of DTMF digits

To configure your DTMF collection to accept a range of digits, such as PINs, you can use the dtmfMinCount and dtmfMaxCount attributes. These attributes inclusively define the lower and upper limits for the number of acceptable digits that can be entered during a DTMF collection session.

In the following example, the caller is prompted to enter their PIN, and can respond with a number that is 4-8 digits long. When one of the following events occurs, a conversation turn is initiated.

• A vgwPostResponseTimeout occurs because Voice Gateway receives no input from the caller.
• A speech utterance is detected
• The maximum number of DTMF digits is collected, dtmfMaxCount
• Or, an inter-digit timeout occurs

{
  "output": {
    "text": {
      "values": [
        "Please enter your PIN."
      ]
    },
    "vgwAction": {
      "command": "vgwActCollectDTMF",
      "parameters": {
        "dtmfMinCount": "4",
        "dtmfMaxCount": "8",
        "dtmfInterDigitTimeoutCount": "1000"

      }
    }
  }
}

Using an action to collect a variable number of digits and end the collection with a termination key

You can set the DTMF collection to end when callers press a termination key or after they finish DTMF input.

• dtmfTermKey- The termination key that a user presses to indicate that they finished DTMF entry.
• dtmfInterDigitTimeoutCount - The amount of time in milliseconds to wait for a new DTMF digit after a DTMF digit is received.

If you don't use the action tag parameters to configure the inter-digit timeout for DTMF collection, Voice Gateway uses the value from vgwPostResponseTimeout by default.

Avoid Trouble: dtmfInterDigitTimeoutCount is only enabled and vgwPostResponseTimeout is disabled after the first DTMF digit is received.

Collecting a single DTMF digit on each conversation turn

You can configure Voice Gateway to pause and unpause a DTMF collection session, by using the vgwActPauseDTMF and vgwActUnPauseDTMF action tags. If you don't pause DTMF collection, Voice Gateway initiates a conversation turn for every DTMF digit that it receives. Voice Gateway also queues any DTMF digits that are received while a conversation turn is active so that no DTMF digits are lost. When DTMF isn't paused, you can use DTMF for voice bots to immediately opt out if a DTMF key of 0 is received at any point during the call.

If DTMF is paused, your collection does not receive any DTMF.