spandsp 0.0.6
Bell MF tone generation

What does it do?

The Bell MF tone generation module provides for the generation of the repertoire of 15 dual tones needs for various Bell MF signalling protocols.

How does it work?

Basic Bell MF tone generation specs:

  • Tone on time = KP: 100+-7ms. All other signals: 68+-7ms
  • Tone off time (between digits) = 68+-7ms
  • Frequency tolerance +- 1.5%
  • Signal level -7+-1dBm per frequency