Synxcom SM9234D, Руководство пользователя

Страница: 90 / 216

AT Commands
Page 90
+MRR: Report Syntax
Response: +MRR: <tx_rate>,<rx_rate>
<tx_rate> Decimal transmit rate in bits/s.
<rx_rate> Decimal receive rate in bits/s
Example: +MRR: 28800, 48000
%E - Enable/Disable Line Quality Monitor and Auto-Retrain or Fallback/Fall
Forward
Controls whether or not the modem will automatically monitor the line quality and
request a retrain (%E1) or fall back when line quality is insufficient or fall forward
when line quality is sufficient (%E2). The parameter value, if valid, is written to
S41, bits 2 and 6.
If enabled, the modem attempts to retrain for a maximum of 30 seconds.
Syntax
%E<value>
Defined Value
<value> Decimal number corresponding to the selected option.
0 Disable line quality monitor and auto-retrain.
1 Enable line quality monitor and auto-retrain.
2 Enable line quality monitor and fallback/fall forward.
(Default.)
Result Codes
OK <value> = 0, 1, or 2.
ERROR Otherwise.
Fallback/Fall Forward. When %E2 is active, the modem monitors the line
quality (EQM). When line quality is insufficient, the modem will initiate a rate
renegotiation to a lower speed within the V.34/V.32bis/V.32 (RC336) modulation
speeds. The modem will keep falling back within the current modulation if
necessary until the speed reaches 2400 bps (V.34) or 4800 bps (V.32). Below this
rate, the modem will only do retrains if EQM thresholds are exceeded. If the EQM
is sufficient for at least one minute, the modem will initiate a rate renegotiation to a
higher speed within the current modulation speeds. The rate renegotiations will be
done without a retrain if a V.32bis connection is established.
Speeds attempted during fallback/fall forward are those shown to be available in
the rate sequences exchanged during the initial connection. Fallback/fall forward is
available in error correction and normal modes, but not in direct mode or
synchronous mode with external clocks.