Chapter 1 – AT Commands, S-Registers, and Result Codes
Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H)
24
+DR
V.44 Data Compression Reporting
Description:
Enables or disables the V.44 data compression report. If the compression report is
enabled, the +DR:<type> intermediate result code reports the current DCE-DCE data
compression type. It is issued after the Error Control Report (+ER) and before the
final result code (e.g., CONNECT).
Syntax: AT+DR=<value>
Values:
0
Disables the V.44 compression report.
1
Enables the V.44 compression report.
Default: 0
Reporting
:
+DR?
Reports current or selected values.
+DR=?
Reports supported parameter values.
Result Codes:
OK if <value> = 0, 1.
ERROR if <value>
≠
0, 1.
+DR: NONE Data compression not in use.
+DR: V42B V.42bis is in use in both directions.
+DR: V44
V.44 is in use in both directions.
+DS
V.42bis Data Compression
Description:
This extended-format compound parameter controls the V.42bis data compression
function if this function is provided in the modem.
Syntax: AT+DS=<direction>,<compr_neg>,<max_dict>,<max_string>
<direction> Values:
Specifies the desired direction(s) of operation of the data compression function
from the DTE point of view.
0
Do not negotiate V.42 bis compression.
3
Modem accepts V.42 bis compression in both directions. Default.
<compr_neg> Values: Specifies whether or not the modem should continue to operate if the desired
result is not obtained.
0
Do not disconnect if V.42bis is not negotiated by the remote modem as
specified in <direction>. Default.
<
max_dict> Values:
Specifies maximum number of dictionary entries (2048 entries) negotiated. May
be used by the DTE to limit the code word size transmitted, based on its
knowledge of the nature of the data to be transmitted. Default = 2048.
<max_string> Values: Specifies maximum string length (32 bytes) to be negotiated. Default = 32.
Reporting:
+DS?
Reports current or selected values.
+DS=?
Reports allowed parameter values.
Result Codes:
OK
ERROR
electronic components distributor