Generate Touch Tone Phone System DTMF Signals

[Now_With_Underscores]

Overview

This VI Generates DMTF Signals according to which numeric keypad option you press.

Description

Touch Tone phone systems use Dual-Tone Multi-Frequency signals to transfer user keystrokes across the phone system.  This example shows how to generate these signals using a multifunction DAQ analog output.  This will allow you to dial phone numbers using any DAQ board that supports non-regeneration and hardware-timed analog output. Specifically this VI generates two sine waves according to what two frequencies the key pressed is associated with, adds them together, and outputs them to the Analog Output of the DAQ card. Additionally this VI calculates the FFT of the output to show the frequency peaks corresponding to the Keypad input.

Requirements

Software

• LabVIEW 8.6 or compatible
  
• DAQmx 8.7.2 or compatible

Hardware

• NI DAQ card with Non-Regenerative Analog Output

Steps to Implement or Execute Code

1. Open and Run the VI
   

Additional Information or References

**This document has been updated to meet the current required format for the NI Code Exchange.**

[Todd S.]

Screen shot this bad-boy when you have a chance.

[Snowman 6008]

Would you mind giving us some helpful hints getting started creating DTMF signals with CVI ?

http://forums.ni.com/ni/board/message?board.id=180&message.id=41785&requireLogin=False

[Ryan_T]

Could you post the code again?  The link to the ZIP file appears broken.  Awesome example!

[Sarah_Y]

Exactly what RyanT said, this example is awesome, but the link to the zip file is broken.  Can you repost it?  Thanks!

[Now_With_Underscores]

There you go.  Have a great day!