SERIES II INTELLIGENT DATA/FAX MODEMS

Appendix B - Dial Pulse and Tone-Dial Frequencies

Dial Pulses

Closed

Open

B

A

Digit 2

Digit 1

In the example above, the digit 2 is pulse dialed, followed by the digit 1. Each pulse consists of an A mSec open and a B mSec closed, where A will be either 60 or 67 mSec and B will be either 40 or 33 mSec, for a total of 100 mSec per pulse, or a rate of 10 pulses per second. The interdigital pause time is 800 mSec The pulse ratios are controlled

by the &P command.

Tone Dial Frequencies

Hz

697

770

852

941

Hz

1

4

7

*

1209

 

Digits

 

 

 

2

 

3

 

 

 

 

 

 

5

 

6

 

 

 

 

 

 

8

 

9

 

 

 

 

 

 

0

 

#

 

 

 

1336 1477

A

B

C

D

1633

150

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Image 151
Black Box MD1641A, MD1640A manual Appendix B Dial Pulse and Tone-Dial Frequencies, Dial Pulses