Technical data

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The AncVoice Coder - 2400 specialized digital telephone set has been designed for
operation in public telephone networks, either directly connected to the ATX, or connected
via a private ATX – using the two-wire connection method. Power for the unit is supplied
from 220V±10% AC via an adapter.
The phone can work either in the standard open mode (in this case, additional services
are available when a correct button – labeled in accordance with internationally accepted
button designation – is pressed), or in the secure mode – when communicating with another
user who has a similar phone set, after a simple procedure of coordinated switching of both
phones in the secure communications mode.
The phone allows to store up to 16 phone numbers of other users in the non-volatile
memory, and to program the initial status of the phone set (the dialing mode, volume levels,
etc.) to which the unit will be reset automatically after each conversation. Loaded information
will be preserved even if the unit was disconnected from the power supply after the last
programming of the internal non-volatile memory of the phone.
The unit belongs to the class of complex electronic devices, known as
hardware/software complexes. It is built on the basis of digital signal processors and has been
designed for a long-term period of operation, provided that the service and maintenance rules
are observed. Take the usual precautions for electronic and computer equipment, when
working with the phone – such as protect it against thermal and mechanical damage, from
moisture and harmful chemically active substances, make sure the voltage of the electric
power supply system is correct, etc.
Programming the non-volatile memory
Anc Voice Coder - 2400 allows the user to set a required initial sound volume of the
ring and the speaker, to select the dialing method used in the telephone network - pulse or
tone, and to set the rate of voice data transmission in the secure mode (2400 or 4800 bits per
second) and the data exchange protocol for the modem - V34, V32, V22bis.
It is possible to quickly change the operating parameters of the telephone set (for
example, the rate and protocol of the modem exchange), re-programming the unit without
having to break the connection with a remote subscriber, if the phone is working in the open
mode.
Secure communication modes
Use the following guidelines when selecting the right operating mode. If the
connection is established via good-quality communication channels, it is recommended to
select the mode of operation at 4.8 Kbps. For secure conversations with a good quality of
speech transmission, one of the following modes should be used:
sec mode 1 - V34 recommendation (takes 17-20 seconds to switch into the secure mode);
sec mode 2 - V32 recommendation (takes 12-15 seconds to switch into the secure mode),
it is used for long-distance connections, where there is usually a lot of repeater devices.
If the connection is established via poor-quality communication channels, for a stable
connection it is recommended to select the mode of operation at 2.4 Kbps and to use:
sec mode 3 - V34 recommendation (takes 18-20 seconds to switch into the secure mode);
in this case, if the modems have established a connection, it is practically impossible that
the secure link may be broken due to channel distortion;