Data Compression - insys icom 56k Manual

Functions
11.8

Data Compression

The INSYS Modem 56k AC/DC 4.2 supports various data compression types.
During the connection setup, it will automatically detect the type of data
compression used by the remote terminal, or it is set to a certain type of data
compression. Data compression is only available for error corrected connections.
To be able to use data compression, both sides (sender and recipient) must be able
to at least recognize and support the same data compression mode.
The default setting is the automatic selection of MNP 5 and V.42bis and V.44 data
compression (AT%C3).
Configuration with HSComm
Direct configuration with the HSComm is not intended. The AT
command to define a fixed baud rate can be sent to the INSYS Modem
56k AC/DC 4.2 via the entry field "Initialization string" (Page 36, Figure 7:
HSComm Modem - Modem, Position 13).
Configuration with AT commands
To select the compression type, use:
To completely switch off the compression,
use the following commands:
To select the MNP 5 compression:
To select the V.42bis and V.44 data
compression if they are switched on (see
below):
To select the V42bis and MNP 5 data
compression if V42bis compression is
switched on (see below):
To switch on V.42bis compression:
To switch on V.44 compression:
To switch off V.42bis compression:
To switch off V.44 compression:
48
INSYS Modem 56k AC/DC 4.2
AT%C<n>
AT%C0
AT+DS44=0
AT%C1
AT%C2
AT%C3
AT%C2
AT+DS44=3
AT%C0
AT+DS44=0