Share via

dtmf Element

  • Article

This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

Used in telephony applications to specify dual tone multi-frequency (DTMF) inputs and how to handle the collected results.

Syntax

<dtmf attributes>
   <grammar attributes />  // Specifies grammar resources
   <bind attributes />     // Copies recognition results to page elements or calls a methods of the target element
   <param attributes />    // Specifies platform configuration parameters 
</dtmf>

Members

The dtmf element consists of the following members.

Content Description

grammar

Specifies input grammar resources.

bind

Copies one semantic element of recognition results to an HTML page element or calls a method of the target element.

param

Specifies a Speech Server configuration parameter.
Attribute Description

id

Identifies the dtmf element.

endsilence

Specifies, in milliseconds, the time period when DTMF input matches the grammar but further input is still possible.

initialtimeout

Specifies, in milliseconds, the time-out period for receiving the first DTMF keypress.

interdigittimeout

Specifies, in milliseconds, the time-out period between DTMF keypresses after the first keypress is recognized.

preflush

Specifies whether to automatically flush the DTMF buffer on the underlying telephony interface card before activation.
Property Description

dtmfresult

Contains the results of DTMF collection.

status

Indicates the success of a DTMF collection by the telephony platform.

text

Contains a string holding the DTMF digits collected.
Method Description

Start

Starts the DTMF collection session.

Stop

Stops the DTMF collection session.

Flush

Flushes the DTMF collection buffer.
Event Description

onerror

Occurs when the DTMF collection or recognition process encounters a serious or fatal error.

onkeypress

Occurs every time a user presses a grammar-defined DTMF key.

onnoreco

Occurs when a DTMF key is pressed that is not valid according to the DTMF grammar or when the interdigittimeout period is exceeded.

onreco

Occurs when a DTMF session ends with a recognition.

onsilence

Occurs when no DTMF keys have been pressed before the initialtimeout expires.
Event Diagram Description

dtmf Event Diagram

Illustrates the event timelines associated with the dtmf element.

dtmf/listen Interaction

Illustrates the interaction timelines that occur when a dtmf element and a listen element are concurrently active.

Remarks

The dtmf element creates an object for the recognition of DTMF touch-tone signals.

Activate the dtmf element using scripting or inline markup language syntax. When activated and a key is pressed, DTMF input can interrupt any active prompt if the bargein attribute of the prompt element is set to true.

Example

The following code demonstrates the use of the dtmf element.

<html xmlns:salt="http://www.saltforum.org/2002/SALT">
    ...
    <body>
        <input type="text" name="iptAreaCode" onFocus="dtmfAreaCode.Start()" />
        <input type="text" name="iptPhoneNumber" />
        ...
        <salt:dtmf id="dtmfAreaCode" onkeypress="dtmfKeyPressHandler()" onreco="dtmfPhoneNumber.Start()"        onsilence="dtmfSilenceHandler()" onerror="dtmfErrorHandler()" onnoreco="dtmfErrorHandler()"        initialtimeout="5000" interdigittimeout="2000" preflush="true">
            <!-- grammar result will contain "smlAreaCode" node -->
            <salt:grammar src="3digits.grxml" />
            <salt:bind value="//smlAreaCode" targetelement="iptAreaCode" />
        </salt:dtmf>
        <salt:dtmf id="dtmfPhoneNumber" onkeypress="dtmfKeyPressHandler()" onerror="dtmfErrorHandler()"        initialtimeout="5000" interdigittimeout="2000" preflush="true">
            <!-- grammar result will contain "smlPhoneNumber" node -->
            <salt:grammar src="7digits.grxml" />
            <salt:bind value="//smlPhoneNumber" targetelement="iptPhoneNumber" />
        </salt:dtmf>
        <script language="jscript">
        <!--
            function dtmfSilenceHandler() {
                ...
            }
            function dtmfErrorHandler() {
                ...
            }
            function dtmfKeyPressHandler() {
        ...
            }
        -->
        </script>
    <body>
</html>

See Also

Concepts

listen Element
prompt Element
smex Element