CHAPTER 2: AT Commands
23
2.6 Data Compression Commands
Commands:
+DR
Data Compression Reporting
Values:
0, 1
Default:
This extended format numeric parameter controls whether or not the
extended-DR: intermediate result code is transmitted from the
modem to the DTE. S95 bit 5 is reset to 0 for +DR=0 and is set to a 1 for
+DR=1. The more recent setting of +DR or S95 bit 5, and the W
command setting, determines the actual data compression result code
reporting (see S95 Parameter and W Command).
+DR0
Data compression reporting disabled (no +DR result code
transmitted).
+DR1
Data compression reporting enabled (+DR result code
transmitted).
+DR
<type> Intermediate result code. The +DR: <type> reported
represents the current (negotiated or renegotiated)
modem–modem data compression type. If enabled, the
intermediate result code is transmitted at the point after error
control negotiation (handshaking) at which time the modem
has determined which data compression technique will be used
(if any) and the direction of operation. The +DR intermediate
result code, if enabled, is issued after the error control report
(+ER) and before the final result code (for example,
CONNECT).
Report Commands:
+DR?
Reports current or selected values.
+DR=? Reports supported range of parameter values.
Command:
+DS
Data Compression
Values:
<direction> Specifies the desired direction(s) of operation of the
data compression function; from the DTE point of view.
+DS0
Negotiated; no compression (V.42bis P0=0).
+DS3
Both directions, accept any direction (V.42bis P0=11).
<compr_neg> Specifies whether or not the modem should continue to
operate if the desired result is not obtained.
+DS0
Do not disconnect if V.42bis is not negotiated by the remote
modem as specified in <direction>.
<max_dict> Specifies maximum number of dictionary entries (2048
entries) that should be negotiated (may be used by the DTE to limit
the code word size transmitted, based on its knowledge of the data to
be transmitted).
<max_string> Specifies maximum string length (32 bytes) to be
negotiated (V.42bis P2).
Default:
3
Description:
This extended-format compound parameter controls the V.42bis data
compression function if provided in the modem. It accepts four
numeric subparameters:
+DS=[<direction>[,<compr_neg>[,<max_dict>[,<max_string>]]]]
Report Commands:
+DS?
Reports current of selected values.
+DS=? Reports supported range of parameter values.
Summary of Contents for MD1650A-JP
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