Rockwell RFX144V24-S23, Designer'S Manual, Page: 14 / 198

RFX144V24-S23 and RFX96V24-S23 Modem Designer’s Guide
1-6 1070
Receive Dynamic Range
The receiver satisfies PSTN performance requirements for received line signal levels from 0 dBm to -43 dBm measured at
the Receiver Analog Input (RXA) input. An external input buffer and filter must be supplied between RXA and RIN.
The default values of the programmable Received Line Signal Detector (~RLSD) turn-on and turn-off threshold levels are -43
dBm and -48 dBm, respectively. The ~RLSD threshold levels can be programmed over the following range:
Turn on: -10 dBm to -47 dBm
Turn off: -10 dBm to -52 dBm
Receiver Timing
The timing recovery circuit can track a ±0.01% frequency error in the associated transmit timing source.
Carrier Recovery
The carrier recovery circuit can track a ±7 Hz frequency offset in the received carrier.
Clamping
Received Data (RXD) is clamped to a constant mark whenever ~RLSD is off.
Tone Detectors
The tone detector signal path is separate from the main received signal path thus enabling tone detection to be independent
of the receiver status. The tone detectors operate in all modes, except V.23 without tone detectors, and speakerphone
where only tone detector one is operational. The filter coefficients of each filter are host programmable in RAM.
Table 1-2. Configurations, Signaling Rates, and Data Rates
Configuration Modulation
Carrier
Frequency (Hz)
±0.01%
Data Rate (bps)
±0.01%
Baud
(Symbols/Sec.)
Bits
/Symbol
Constellation
Points
V.17/V.33 14400
2
TCM 1700 or 1800 14400 2400 6 128
V.17/V.33 12000
2
TCM 1700 or 1800 12000 2400 5 64
V.17 9600
2
TCM 1700 or 1800 9600 2400 4 32
V.17 7200
2
TCM 1700 or 1800 7200 2400 3 16
V.29 9600 QAM 1700 9600 2400 4 16
V.29 7200 QAM 1700 7200 2400 3 8
V.29 4800 QAM 1700 4800 2400 2 4
V.27 ter 4800 DPSK 1800 4800 1600 3 8
V.27 ter 2400 DPSK 1800 2400 1200 2 4
V.21 Channel 2 300 FSK 1650, 1850 300 300 1 –
V.23 receive HDX FSK 1300, 2100 1200 1200 1 –
V.23 1200/75
3
FSK 1300, 2100/
390, 450
1200/75 1200/75 1
–
Notes:
1. Modulation legend:
QAM: Quadrature Amplitude Modulation
DPSK: Differential Phase Shift Keying
FSK: Frequency Shift Keying
TCM: Trellis-Coded Modulation
2. RFX144 models only.
3. V.23 models only.