Tainet ITM-3296bis, Руководство пользователя

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GENERAL INFORMATION AND FEATURES 4-3
4.4 Answer Mode VS. Originate Mode
While using the dial line, there must be a modem initiating the call, once the
exchanger recognizes the number, it connects the circuit to the answering modem
with ring signals. Answering modem can pick up the call manually or automatically.
Afterward, it issues the answer tone to connect with the originate modem. Usually, we
call the modem which dials the call as originate mode and the other one as answer
mode. According to the role of the connection the training sequence and working
frequency band of either modem is different from each other even operating with
leased line.
With 2/4-wire full-duplex operation such as V.21, V.22,V.22bis, V.23,V.32, V.32bis,
V.34, Bell 103, and Bell 212A, there should be an originate mode and an answer
mode. However, with other 4-wire full-duplex operations such as V.26, V.27bis, V.29
and V.33 the designation of originate and answer ends is not necessary.
You may find the information of originate/answer settings in the "ORG/ANS MODE"
column of "CONFIG MODEM" MENU. Note that the modem will automatically
determine either mode whenever you use the "AT" commands, front panel dialing, or
auto answering.
4.5 Synchronous VS. Asynchronous
The data formats of both connecting modems must be exactly the same in order to
exchange data with each other.
There are synchronous and asynchronous data formats. The common personal
computers and terminals are asynchronous. Whereas, the host computers and their
terminals are often synchronous.
For most multiplexes, the connecting modems should be synchronous. However, the
user should know the type of the data terminal equipment (DTE) to get proper
operation.
Except V.21, V.23, and Bell 103 which only can operate in asynchronous mode, other
protocols can run in either mode.
About the settings of this issue, you may find it at "Data Format" column of "CONFIG
DTE" menu. Note that if the asynchronous mode is selected, you need to set " Data
Bits ", " DTE Speed", "Parity" and "Stop Bit" as well. On the other hand, if you
operate the modem with "AT" command, it will automatically determine these
parameters.