User guide

MultiModemUSB User Guide
MT4X56USB50
S38 decimal 0–23 1 Sets “downstream” data rate where K56flex provides rates
of 32,000 to 56,000 in 2,000 bps increments, V.90 provides
rates of 28,000 to 56,000 bps in increments of 1,333 bps.
0 = V.90 disabled
1 = V.90 autorate
K56flex rates
2 = 28,000 bps 2 = 32,000 bps
3 = 29,333 bps 3 = 34,000 bps
4 = 30,666 bps 4 = 36,000 bps
5 = 32,000 bps 5 = 38,000 bps
6 = 33,333 bps 6 = 40,000 bps
7 = 34,666 bps 7 = 42,000 bps
8 = 36,000 bps 8 = 44,000 bps
9 = 37,333 bps 9 = 46,000 bps
10 = 38,666 bps 10 = 48,000 bps
11 = 40,000 bps 11 = 50,000 bps
12 = 41,333 bps 12 = 52,000 bps
13 = 42,666 bps 13 = 54,000 bps
14 = 44,000 bps 14 = 56,000 bps
15 = 45,333 bps
16 = 46,666 bps
17 = 48,000 bps
18 = 49,333 bps
19 = 50,666 bps
20 = 52,000 bps
21 = 53,333 bps
22 = 54,666 bps
23 = 56,000 bps
Upstream data rates
Upstream V.90 data rates are 4800 to 33,600 bps in 2400
bps increments.
S42 decimal 0–1 1 Enables/disables the 56K auto rate. When 56K auto is
disabled, fallback to V.34 is also disabled. 0 = disable;
1 = enable.
S43 decimal 0–1 1 For For testing and debugging only. Enables/disables
V.32bis start-up auto mode operation. 0 = disable; 1 =
enable.
S48 decimal 7 or 128 7 Enables (7) or disables (128) LAPM negotiation. The follow-
ing table lists the S36 and S48 configuration settings for
certain types of connections.
S48=7 S48=128
LAPM or async Async
LAPM or hangup Do not use
LAPM, MNP, or aysnc
LAPM, MNP, or hangup MNP or hangup
MNP or async
S36=0, 2
S36=1, 3
S36=4, 6
S36=5, 7
S89 seconds 0, 5–255 10 Sets the length of time in the off-line command mode before
the modem goes into standby mode. A value of zero
prevents standby mode; a value of 1–4 sets the value to 5.
S108 decimal 0–3, 6, 7 6 Selects the 56K digital loss if using the modem thru a PBX
line. The default value is -6 dB loss, the value used when
calling from a typical POTS line long distance.
0 = -0 dB digital loss, no robbed-bit signaling
1 = -3 dB PBX digital loss
2 = -2 dB digital loss
3 = -3 dB digital loss
6 = -6 dB digital loss
7 = -0 dB digital loss with robbed-bit signaling
S109 decimal 0--2 1 Sets one of three 56K operating modes:
K56flex mode, V.90 mode, or Auto-mode.
S109=2 forces V.90 connections for testing purposes, etc. S109
sets the 56K operating mode as shown below:
0 = V.90 disabled
1 = K56flex or V.90 (Dual mode enabled)
2 = V.90 only (K56flex disabled).