AT Commands
Page 98
3.2.6 Data Compression Commands
This section contains parameters to condition modem use of standard ITU-T
V.42bis Data Compression Procedures.
+DS - Data Compression
This extended-format compound parameter controls the V.42bis data compression
function if provided in the modem. It accepts four numeric subparameters:
Syntax
+DS=[<direction>[,<compr_neg>[,<max_dict>[,<max_string>]]]
]
Defined Value
<direction>
Specifies the desired direction(s) of operation of the data
compression function; from the DTE point of view.
0 Negotiated; no compression (V.42bis P0=0).
3 both directions, accept any direction (V.42bis P0=11).
(Default.)
<compr_neg>
Specifies the desired direction(s) of operation of the data
compression function; from the DTE point of view.
0 Do not disconnect if V.42bis is not negotiated by the
remote modem as specified in <direction>.
<max_dict>
Specifies the maximum number of dictionary entries (2048
entries) which should be negotiated (may be used by the DTE
to limit the codeword size transmitted, based on its knowledge
of the nature of the data to be transmitted).
<max_string>
Specifies the maximum string length (32 bytes) to be
negotiated (V.42bis P2).
Reporting Current or Selected Values
Command:
+DS?
Response:
+DS: <direction>,<compr_neg>,<max_dict>,<max_string>
Example:
+DS: 3,0,2048,32 for the defaults and 2048 entry max
dictionary.
Reporting Supported Range of Parameter Values
Command:
+DS?
Response:
+DS: (<direction> range),(< compr_neg > range),
(<max_dict> range),(<max_string> range)
Example:
+DS: (0,3),(0),(2048),(32)
+DS44 - V.44 Compression Select
This extended-format compound parameter controls the V.44 data compression
function.
Syntax
+DS44=[<direction>[,< compress_negotiation
>[,<capability>[,<max_codewords_tx>
[,<max_codewords_rx>[,<max_string_tx>[,<max_string_rx>[,
<max_history_tx>
[,<max_history_rx>]]]]]]]]]
Defined Value
<direction>
Decimal number that specifies the desired direction(s) of
Summary of Contents for SM9234D
Page 1: ...SM9256D and SM9234D Modems User s Guide 0049 2500 001 Rev B ...
Page 5: ...Page v local or long distance transmission charges ...
Page 6: ......
Page 14: ......
Page 17: ...Introduction Page 17 ...
Page 18: ......
Page 26: ......
Page 28: ...Using the Modem s Auto Connect Feature Page 28 ...
Page 87: ...AT Commands Page 87 example modem models supporting V92 may not support K56 ...
Page 107: ...AT Commands Page 107 Data Transfer Bit error rates for each direction ...
Page 136: ...AT Commands Page 136 S86 26 Remote hangup detected ...
Page 198: ...AT Commands Page 198 OK ERROR If not in Voice Mode ...
Page 213: ...AT Commands Page 213 ...
Page 214: ......