r6781-12 Conexant Systems, Inc., r6781-12 Datasheet - Page 12

• Manufacturer Part Number: r6781-12
• Description: Embedded Modem Family
• Manufacturer: Conexant Systems, Inc.

1.2 Technical Specifications
1.2.8 Transmit Level
1.2.9 Transmit Tones
1.2.10 Receive Level
1.2.11 Receiver Tracking
1-4
Ring Detection
DTMF Dialing
Answer Tone
Calling Tone
Guard Tone
The transmit level is – 10 dBm
using the circuits shown in Appendix A. Carrier and dual tone multi-frequency
(DTMF) transmit levels can be further attenuated using AT%Ln + AT%Dn
commands, respectively. If a higher transmit level is required, an external op amp
can be added.
An answer tone of 2100 Hz (V .22 bis, V .22, or T.30) or 2225 Hz (Bell 212A or
103) is generated.
An 1800 Hz guard tone can be generated in all data modes.
An 1100 Hz (0.5 seconds on, 3 seconds off) calling tone (T.30) is generated in the
originate fax mode.
The receiver satisfies performance requirements for a received signal from
– 9 dBm to – 43 dBm. The carrier detect is ON at – 43 dBm and OFF at – 48 dBm
with a minimum of 2 dB hysteresis.
The modem can accommodate carrier frequency offset up to
transmit timing error of
212A).
Standard DTMF tones (digits 0-9, A, B, C, D, *, and #) or pulses (digits 0-9) can
be generated. Refer to
RING signal is detected from valid high to low transitions on the RING input line
at frequencies of 15.3 Hz to 63 Hz. A RING is valid if the RING ON time is
greater than 0.125 seconds and is followed by a RING OFF time greater than 0.5
seconds.
Table 1-3. Dial Digits/Tone Pairs (1 of 2)
Dial Digit
0
1
2
3
4
5
Conexant
Table
±
0.01% (V .22 bis or V .27 ter) or
1-3.
±
1 dB (at TIP and RING) and can be obtained
Frequency (Hz)
Tone 1
941
697
697
697
770
770
EmbeddedModem Family
±
0.02% (V .22 or Bell
Frequency (Hz)
±
7 Hz, and a
Tone 2
1336
1209
1336
1477
1209
1336
D224ATLVDSC