Raymar Alliance V.32, Инструкция по эксплуатации

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0049-2702-XXX Alliance Series Modems – USER MANUAL 08/05/2010
Rev. A Page 78 of 197
For successful data transfer, these options must be set in the same way on the originating modem
as well – and the speed of the originating modem must be 4800 bps or higher.
Bell 208 Operation
If an answering ALX in V.3x/208 mode detects a Bell 208 modem, it will operate with the
following options set as shown:
•
Data format – synchronous
•
V.13 operation – off
•
Carrier type - switched
The originating Bell 208 modem must be configured to detect the Bell 208 answer tone before it
goes to data mode. (Some 208 modems may not have this option.)
Automatic Fallback
When the ALX is configured for V.3x/208 auto-select mode and is in answer mode, it will not
handshake in V.22bis, Bell 212/103 or V.21/V.22, V.23 mode.
V.13 OPERATION
The ALX modem can be configured for ITU-T V.13 operation (which emulates half duplex
operation) for either point-to-point or multidrop applications. (For configuration details for these
applications, see
V.13 Operation in Chapter 2.) The ALX normally operates in full duplex;
however, some applications (such as certain network environments) may require control of a
remote CD signal by a local Request to Send (RTS) signal. V.13 operation allows a local RTS
control of a remote CD signal without actual ON-OFF switching of the modem carrier.
The following explains how the ALX modem will respond to RTS signals when it is configured
for V.13 operation:
When RTS is raised high by the terminal, the V.13 ON PATTERN will be sent. The modem will
then raise CTS (and data can be sent). When the RTS is brought low, the V.13 IDLE PATTERN
will be sent, and the modem will drop CTS. (If V.13 TX is enabled but the modem data pump is
not ready to send, i.e., if it is training or retraining, raising RTS will cause CTS to be raised, but
the V.13 ON PATTERN will not be sent.) When V.13 RX is enabled, CD will turn ON if the
V.13 ON PATTERN is detected; CD will turn OFF if the V.13 IDLE PATTERN is detected or if
the modem retrains, loses carrier or is reset.