Cabletron Systems CSMIM-T1 - Manual (Page 177)

Registers
CSMIM-T1 Hardware Installation Guide 7-51
This command requires 1200 bps or higher operation with
%F0%L1 set.
Determines how long the modem attempts to establish a V.32,
V.22bis, or V.22 connection before attempting to establish a
V.21 connection. During this period, the modem sends V.22bis
or V.22 carrier.
:T2= n Timer for V.21 Mode During Multi-Protocol Answer
Where n is an integer from 0 to 255 representing tenths of a
second. Default is 0 (V.23 half-duplex disabled).
This command requires 1200 bps or higher operation with
%F0%L1\N3 set.
When the modem is unable to establish a V.32, V.22bis, or a
V.22 connection, :T2 determines how long the modem attempts
to establish a V.21 connection before attempting a V.23
half-duplex connection. During this period, the modem sends
V.21 carrier.
Set :T2=20 (2 seconds) when including V.23 half duplex in the
multi-protocol answer modem.
:T3= n Timer for V.21 and V.23 Answer Tone Duration
Where n is an integer from 0 to 33 (tenths of a second)
Default is 33 (3.3 seconds).
This command requires either V.21 operation (%F0 is set and
the modem speed is 300 bps) or V.23 operation (%Fn, where
n=1, 2, or 3).
When the answering modem is set for V.21 or V.23 operation,
:T3 determines the duration of the V.25 answer tone that is sent
to the originating modem. When :T3 is set to 0, no answer tone
is sent. All V.21 and V.23 answers begin with two seconds of
silence unless :T3 is set to 0.
NOTE
If :T2 is set to 0, V.23 half-duplex connections are not
attempted. The modem attempts to establish a connection for
the length of time specified by register S7 before hanging up.