0049-2702-XXX Alliance Series Modems – USER MANUAL
08/05/2010
Rev. A
Page 120 of 197
Registers S43, S44, S64 and S65 – Rates Controlled by Each:
Register
ALX V.34 and V.34M
All other models
S43
Max. TX DCE rate
Max. DCE rate
S44
Min. TX DCE rate
Min. DCE rate
S64
Max. RX DCE rate
Does not apply
S65
Min. RX DCE rate
Does not apply
The four registers listed above are used to specify the maximum and/or minimum data rate the
ALX will use in handshaking with another modem. (They are Hayes mode equivalents to the
Speed Limit option settings, which are accessible through the front panel LCD.)
The ALX may connect at a rate lower than the specified maximum rate (or higher than the
minimum), depending on the remote modem’s capabilities and line conditions, but will not be
able to connect at a rate higher than the maximum rate or lower than the minimum rate.
For all four registers (S43, S44, S64 and S65), the values that may be stored have the same
definitions – i.e., they correspond to the same data rates – as listed in the table below. However,
the values in each register are applied differently, as indicated in the table above. For example, a
value of 2 in register S43 sets the maximum TX DCE rate to 24.0 Kbps (if the modem is an ALX
V.34 or V.34M), while a value of 2 in register S44 sets the
minimum
TX DCE rate to 24.0 Kbps.
Registers S43, S44, S64 and S65 – Parameters:
S register
value
Data rate, bps
S register
value
Data rate, bps
0 28.8
K 8 9600
1 26.4
K 9 7200
2 24.0
K 10 4800
3 21.6
K 11 2400
4 19.2
K 12 1200
5 16.8
K 13 600
6 14.4
K 14 0-300
7 12.0
K 15
1200/75
Different TX DCE and RX DCE rates are effective only if the Asymmetric Data Rates option is
enabled. If this option is disabled, TX and RX rates are both determined by the
TX
DCE limits.
(The RX DCE setting[s] is ignored.)
The default maximum data rate setting depends on the model:
ALX V.34 and V.34M (TX and RX DCE rate): 0 (28.8 K)
ALX V.32/19.2 and V.32/19.2M:
4
(19.2
K)
ALX V.32/14.4 and V.32/14.4M:
6
(14.4
K)
ALX V.32 and V.32M:
8 (9600 bps)
