Black Box 32144, Руководство пользователя

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109
CHAPTER 5: Hayes Emulation Mode
recognize the tone and indicate a
carrier detect. (The time required
for the absence of a carrier tone to
be recognized is fixed at 0.5
second.)
S10—LOSS OF CARRIER
DELAY. The value in register S10
determines how long the delay will
be from the occurrence of a loss of
carrier until the modem hangs up
the telephone line. A value of 255
disables the modem’s carrier
disconnect option (and line
current option), meaning that the
modem will not hang up in the
absence of carrier or line current.
S11—TONES. This register sets
the spacing of tones used for
dialing. The rate can be slowed by
increasing the value of S11 to the
maximum value, 255. This register
has no effect on pulse dialing,
which is fixed at 10 pulses per
second.
S12—GUARD TIME. This
register is effective for
asynchronous operation only. The
escape guard time delay is required
immediately before and after
entering the escape code;
therefore, the three escape-code
characters must be entered within
the guard time delay of each other.
The unit for this register is 1/50
second (or 20 ms), meaning that
the default value of 50 equals 1
second.
If the guard time is zero, timing
will not be a factor at all. The three
escape characters can occur with
any timing relationship, but they
must be consecutive. Be cautious
when assigning small guard times,
however. You may not be able to
enter three characters fast enough,
especially if the guard time is less
than the time required to transmit
one character at the current
transmission rate.
S18—DIAGNOSTIC TIMER. The
value in register S18 determines
how long a diagnostic test will run.
For example, if S18 is set to 120,
the test (activated by one of the &T
commands) will run for 120
seconds. If S18 is set to zero, the
default, the test timer will be
disabled and the test will run
indefinitely. To terminate a test
when the test timer is disabled, use
the command &T0 or reset the
modem. Register S18 is set to zero
on powerup or by the command
AT Z or AT S18=0.
S25—DELAY TO DTR. The
effect of the value stored in register
S25 is dependent on the operating
mode, as explained below.
Synchronous mode 1: A delay
occurs after a call is established
before the modem examines the
state of DTR. The duration of this
delay is the value specified in S25
(in seconds). This allows the
operator time to disconnect the
modem from an asynchronous data
terminal and attach it to a
synchronous terminal without
forcing the modem back into the
command state.