Chapter 11 – Data Commands
Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I)
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Select Data Compression %C
Description:
This command enables or disables data compression negotiation if this feature is supported on the
product.
Values: <n>
0
no compression (default)
2
V42bis compression if supported
Syntax: Command
syntax:
AT%C<n>
Command
Possible responses
AT%C0
Note: Command
OK
Note: Feature supported
AT%C2
Note: Command
OK
Note: V42bis supported
AT%C?
Note: Current value
2
OK
Note: Command valid
V42bis Data Compression +DS
Description:
This command enables or disables V.42bis data compression if this feature is supported on the product.
Note that the product allows only the MNP2 protocol.
Values:
<
dir
>
Specifies the desired direction(s) of operation of the data compression function; from the
DTE point of view, (default is 3)
0
Negotiated … no compression
1
Transmit only
2
Receive only
3
Both directions, accept any direction. Default.
<
neg
>
Specifies whether or not the DCE should continue to operate if the desired result is not
obtained, (default is 0)
0
Do not disconnect if V.42 bis is not negotiated by the remote DCE as specified in <dir>.
Default.
1
Disconnect if V.42 bis is not negotiated by the remote DCE as specified in
<
dir
>
<
P1 >
Specifies the maximum number of dictionary entries that should be negotiated,
Range is 512 to 2048. Default is 2048.
< P2 >
Specifies the maximum string length to be negotiated. Range is 6 to 250. Default is 20.
Syntax: Command
syntax:
AT+DS=[[<dir>][,[<neg>][,[<P1>][,[<P2>]]]]
Command
Possible responses
AT+DS=?
Note: Test command
+DS: (0-3),(0,1),(512-2048),(6-250)
OK
AT+DS=3,0,2048,250
Note: Set new parameters
OK
Note: Command valid
AT+DS?
Note: Current values
+DS: 3,0,2048,20
OK
Note: Command valid