1.0 Functional Description
RC224ATL/224ATLV
1.2 Technical Specifications
EmbeddedModem Family
1.2.8 Transmit Level
The transmit level is – 10 dBm ± 1 dB (at TIP and RING) and can be obtained
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.
1.2.9 Transmit Tones
Answer Tone
An answer tone of 2100 Hz (V.22 bis, V.22, or T.30) or 2225 Hz (Bell 212A or
103) is generated.
Guard Tone
Calling Tone
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.
1.2.10 Receive Level
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.
1.2.11 Receiver Tracking
The modem can accommodate carrier frequency offset up to ± 7 Hz, and a
transmit timing error of ± 0.01% (V.22 bis or V.27 ter) or ± 0.02% (V.22 or Bell
212A).
DTMF Dialing
Ring Detection
Standard DTMF tones (digits 0-9, A, B, C, D, *, and #) or pulses (digits 0-9) can
be generated. Refer to Table 1-3.
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)
Tone 1
Frequency (Hz)
Tone 2
Frequency (Hz)
Dial Digit
0
1
2
3
4
5
941
697
697
697
770
770
1336
1209
1336
1477
1209
1336
1-4
Conexant
D224ATLVDSC
CONEXANT [ CONEXANT SYSTEMS, INC ]
