INSYS Modem 56k small EU 2.1
Functions
37
12.7
Data Compression
The INSYS Modem 56k small EU 2.1 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 MNP5 and V42.bis and V.44 data com-
pression (
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 small EU 2.1 via
the entry field "Initialization string" (page 26, Figure 5, position 13).
Configuration with AT commands
To select the compression type, use:
AT%C<n>
To completely switch off the compression, use
the following commands:
AT%C0
AT+DS44=0
To select the MNP4 compression:
AT%C1
To select the V42bis and V.44 data compres-
sion if they are switched on (see below):
AT%C2
To select the V42bis and MNP5 data compres-
sion if V42.bis compression is switched on (see
below):
AT%C3
To switch on V.42bis compression:
AT%C2
To switch on V.44 compression:
AT+DS44=3
To switch off V.42bis compression:
AT%C0
To switch off V.44 compression:
AT+DS44=0
