Command Reference Guide

3Com Router 5000 Family and Router 6000 Family dtmf threshold ● 143
Command Reference
3 The lower threshold of ROWMAX / COLMAX when COLMAX >=
ROWMAX. The function of this parameter is similar to that of index
2, except that they are in reverse. The ratio must be greater than this
threshold for the input signal to be recognized as a DTMF digit.
The threshold is an integer in the range -18 to -3 dB and defaults to
-9 dB. A lower value means increased detection reliability but
decreased sensitivity.
4 The upper threshold of the ratio of the second largest energy level
from the row frequency group to ROWMAX. The ratio must be
lower than this threshold for the input signal to be recognized as a
DTMF digit.
The threshold is an integer in the range -18 to -3 dB and defaults to
-9 dB. A smaller value means increased detection reliability but
decreased sensitivity.
5 The upper threshold of the ratio of the second largest energy level
from the column frequency group to COLMAX. The ratio must be
lower than this threshold for the input signal to be recognized as a
DTMF digit.
The threshold is an integer in the range -18 to -3 dB and defaults to
-9 dB. A smaller value means increased detection reliability but
decreased sensitivity.
6 The upper threshold of ROW2nd / ROWMAX. An input signal is
recognized as a DTMF digit only when ROW2nd / ROWMAX < 6.
The threshold is an integer in the range -18 to -3 dB and defaults to
-3 dB. A smaller value means increased detection reliability but
decreased sensitivity.
7 The upper threshold of COL2nd / COLMAX. The ratio must be lower
than this threshold for the input signal to be recognized as a DTMF
digit.
The threshold is an integer in the range -18 to -3 dB and defaults to
-12 dB. A smaller value means increased detection reliability but
decreased sensitivity.
8 The upper threshold of the ratio of the maximum value of the larger
energy level among two extra specified frequency points to max
(ROWMAX, COLMAX). The ratio must be greater than this threshold
for the input signal to be recognized as a DTMF digit.
The threshold is an integer in the range -18 to -3 dB and defaults to
-12 dB. A smaller value means increased detection reliability but
decreased sensitivity.
9 The lower threshold of the DTMF signal duration. The duration of
DTMF key tone must be larger than this threshold for the input
signal to be recognized as a DTMF digit.
The threshold is in the range 30 to 150 milliseconds and defaults to
30 milliseconds. A greater value means increased detection reliability
but decreased sensitivity.
10 The frequency of the first extra frequency point specified for
detection. It is an integer in the range 300 to 3400 Hz and defaults
to 300 Hz.
In addition, it must be a value beyond the row and column
frequency groups.
11 The frequency of the second extra frequency point specified for
detection. It is an integer in the range 300 to 3400 Hz and defaults
to 3200 Hz.
In addition, it must be a value beyond the row and column
frequency groups.
Index numbers Indicates