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6179-2201
%En – 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 qual-
ity 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.
%E0 Disable line quality monitor and auto-retrain.
%E1 Enable line quality monitor and auto-retrain.
%E2 Enable line quality monitor and fallback/fall forward. (
Default
)
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.32 bis/V.32 (TD-33) modulation speeds. The modem will keep
falling back within the current modulation if necessary until the speed reaches 2 400 bit/s
(V.34) or 4 800 bit/s (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.32 bis 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.
&Fn – Restore Factory Configuration (Profile)
The modem loads the factory default configuration (profile). The factory defaults are
identified for each command and in the S-Register descriptions. A configuration (profile)
consists of a subset of S-Registers.
&F0 Restore factory configuration 0.
&F1 Restore factory configuration 1.
&Gn – Select Guard Tone
The modem generates the guard tone selected by this command according to the parame-
ter supplied (DPSK modulation modes only). The parameter value, if valid, is written to
S23 bits 6 and 7.
&G0 Disables guard tone. (
Default
).
&G1 Disables guard tone.
&G2 Selects 1 800 Hz guard tone.
This command may not be permitted in some countries.
