Intel MD566X User Manual
Page 56
56K V.92 Data, Fax, and Voice Chipset
56
Intel Confidential
Programmer’s Guide
+MS=m
see “m”
Modulation Selection: This command sets the type of modulation used and the
send and receive speeds. Settings for Bn, +MS=m, Nn and S37 determine the al-
lowable modem connections. Nn performs the same function as the +MS=m
rameter.
Modems using MD566X chipsets can be configured by the +MS=m command to
support only asymmetrical or symmetrical connections. The transmit and receive
speeds are the same in symmetrical connections and different in asymmetrical con-
nections. The type of connection is set by the
default to the ITU-T V.90 or V.92 mode depending on firmware version. If the con-
nection is non-V.90/V.92 the chipsets fall back to V.34 mode. Note that the transmit-
ter speed and receiver speeds typically are different for most V.34 connections over
the PSTN.
The +MS command sets the modulation speeds in the V.34 chipsets; however, B0
also must be sent to set the modulation to V.22. Sending B1 sets the modulation to
Bell 212. These commands can be typed before or after the +MS command. For ex-
ample, to set the modulation to ITU-T V.22:
+MS = V22, 1, 1200, 1200; B0
To check the settings for the +MS command, type AT+MS?
m =
Defaults: m = V90, 1, 0, 0
Approved codes are shown in the following table. The modem can switch automati-
cally between some types.
Description
V21
V.21 300 bps
V22
V.22 1200 bps
V22B
V.22 bis 1200 and 2400 bps
V23C
V.23, with constant carrier; 1200 bps forward and 75 bps reverse
V32
V.32 4800 and 9600 bps
V32B
V.32 bis 7200, 9600, 12,000, and 14,400 bps
V34
V.34 asymmetrical connections: 2400, 4800, 7200, 9600, 12,000,
14,400, 16,800, 19,200, 21,600, 24,000, 26,400, and 28,800 bps
V34S
V.34 symmetrical-only connections: 2400, 4800, 7200, 9600,
12,000, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400, 28,800
bps
V34B
V.34 extended asymmetrical connections: 2400, 4800, 7200, 9600,
12,000, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400, 28,800,
31,200, and 33,600 bps
V34BS
V.34 extended symmetrical connections: 2400, 4800, 7200, 9600,
12,000, 14,400, 16,800, 19,200, 21,600, 24,000, 26,400, 28,800,
31,200, and 33,600 bps
Table 3-4.
Data Mode Command Descriptions (Continued)