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Welcome to 56K Information Access

Product Features

Installation for All Operating Systems

Troubleshooting

Technical Reference >

Introduction to Syntax and Procedures

Data Command Set

Result Codes

Glossary

Regulatory Information

Limited Warranty

Modulation Control Commands

+MS - Modulation Selection

This extended-format compound parameter controls the manner of operation of the modulation capabilities in the modem. It accepts six subparameters.

Syntax

+MS=[<carrier>[,<automode>[,<min_tx_rate>[,<min_rx_rate>[,<max_rx_rate>]]]]]
Where possible<carrier>,<min_tx_rate>,<max_tx_rate>,<min_rx_rate>, and <max_rx_rate> values are listed in Table 3-2.

Modulation
<carrier>
Possible (<min_rx_rate>,<min_rx_rate>,<min_tx_rate>,<man_tx_rate>) Rates (bps)
Bell 103 B103 300
Bell 212 B212 1200 Rx/75 Tx or 75 Rx/1200 Tx
V.21 V21 300
V.22 V22 2400 or 1200
V.23 V23C 1200
V.32 V32 9600 or 4800
V.32 bis V32B 14400, 12000, 9600, 6600, or 4800
V.34 V34 33600, 31200, 28800, 26400, 24000, 21600, 19200, 16800, 14400, 12000, 9600, 6600, 4800, or 2400
K56flex K56 56000, 54000, 52000, 50000, 48000, 46000, 44000, 42000, 40000, 38000, 36000, 34000, 32000
V.90 V90 56000, 54667, 53333, 52000, 50667, 49333, 48000, 46667, 45333, 44000, 42667, 41333, 40000, 38667, 37333, 36000, 34667, 33333, 32000, 30667, 29333, 28000
V.92 downstream V92 56000, 54667, 53333, 52000, 50667, 49333, 48000, 46667, 45333, 44000, 42667, 41333, 40000, 38667, 37333, 36000, 34667, 33333, 32000, 30667, 29333, 28000
V.92 upstream V92 48000, 46667, 45333, 44000, 42667, 41333, 40000, 38667, 37333, 36000, 34667, 33333, 32000, 30667, 29333, 28000, 26667, 25333, 24000
Note: Some <carrier> values may not be supported by certain model models. For example, modem models supporting V92 may not support K56.

Defined Values

<value> A string which specifies the preferred modem carrier to use in originating or answering a connection. <carrier> values are strings of up to eight characters, consisting only of numeric digits and upper case letters. <carrier> values for ITU standard modulations take the form: <letter><1-4digits><other letters as needed>. Defined values are listed in Table 3-2.

<automode> A numeric value which enables or disables automatic modulation negotiation (e.g., ITU-T V.32bis Annex A or V.8).

0

Automode disabled.

1

Automode enabled. (default)

<min_rx_rate> and <max_rx_rate> Numeric values which specify the lowest (<min_rx_rate>) and highest (<max_rx_rate>) rate at which the modem may establish a receive connection. May be used to condition distinct limits for the receive direction as distinct from the transmit direction. Values for this subparameter are decimal encoded, in units of bit/s. The possible values for each modulation are listed in Table 3-2. Actual values will be limited to possible values corresponding to the entered and fall-back as determined during operation. (Default = lowest (<min_rx_rate>) and highest (<max_rx_rate>) rate supported by the selected carrier.)

<min_tx_rate> and <max_tx_rate> Numeric values which specify the lowest (<min_tx_rate>) and highest (<max_tx_rate>) rate at which the modem may establish a transmit connection. Non-zero values for this subparameter are decimal encoded, in units of bit/s. The possible values for each modulation are listed in Table 3-2. Actual values will be limited to possible values corresponding to the entered and fall-back as determined during operation. (Default = lowest (<min_tx_rate>) and highest (<max_tx_rate>) rate supported by the selected carrier.)

Reporting Current or Selected Values

Command: +MS?
Response: +MS:,<carrier>,<automode>,<min_tx_rate> <max_tx_rate>,<min_rx_rate>,<max_rx_rate>

Note: The current active settings are reported under control of the +MR parameter.

Example: +MS: K56, 1,300,33600,300,56000

For default values. This example allows maximum system flexibility to determine optimal receive and transmit rates during operation.

Reporting Supported Range of Parameter Values

Command: +MS=?
Response: +MS: (< carrier> range),(<automode> range),(<min_tx_rate> range), ( <max_tx_rate> range), ( <min_rx_rate> range), (<max_rx_rate> range)

Example 1: +MS:(B103,B212,V21,V22,V22B,V23C,V32,V32B,V34, K56,V90),(0,1),(300-33600),(300-33600),(300-56000),(300-56000)

Example 2: +MS:(B103,B212,V21,V22,V22B,V23C,V32,V32B,V34, V90,V92),(0,1),(300-33600),(300-33600),(300-56000),(300-56000)

Result Codes

OK

Valid subparameter string

ERROR

Otherwise


+MR - Modulation Reporting Control

This extended-format numeric parameter controls whether or not the extended-format +MCR:<carrier> and +MRR:<rate> intermediate result codes are transmitted from the modem to the DTE. If enabled, +MCR: <carrier> and +MRR:<rate> intermediate result codes represent the current (negotiated or renegotiated) modulation<carrier> and <rate> that are transmitted at the point during connect negotiation (handshaking) at which the modem has determined which modulation and rate will be used, i.e., before any Error Control or Data Compression reports are transmitted, and before any final result code (e.g., CONNECT) is transmitted.

S95 bit 2 is reset to 0 for +MR=0 and is set to a 1 for +MR=1 or +MR=2. The more recent setting of +MR or S95 bit 2, and the W command setting, determines modulation result code reporting (see S95 Parameter and W Command).

Syntax

+MR=[<value>]

Defined Values

<value> A decimal number corresponding to the selected option:

0

Disables reporting of modulation connection (+MCR: and +MRR: are not transmitted). (Default.)

1
Enables reporting of modulation connection (+MCR: and +MRR: are transmitted with tx rate, rx rate).
2

Enables reporting of modulation connection (+MCR: and +MRR: are transmitted with rx rate only).

Reporting Current or Selected Values

Command: +MR?
Response: +MR: <current value>
Example: +MR: 0 For default setting

Reporting Supported Range of Parameter Values

Command: +MR=?
Response: +MR: (<value>range)
Example: +MR: (0-2)


+MCR: Report Syntax

Response: +MCR: <carrier>

<carrier> Alphanumeric code corresponding to the reported carrier. Defined values are:

B103 For Bell 103
B212 For Bell 212
V21 For V.21
V22 For V.22
V22B For V.22bis
V23C For V.23
V32 For V.32
V32B For V.32bis
V34 For V.34
K56 For K56flex
V90 For V.90
V92 For V.92


+MRR: Report Syntax

Response: +MRR: <tx_rate>, <rx_rate>
<rx_rate> Decimal transmit rate in bits/s.
<rx_rate> Decimal receive rate in bits/s.
Example: +MRR: 28800, 48000


B - CCITT or Bell

When the modem is configured to allow either option, the modem will select Bell or CCITT modulation for a line speed connection of 300 or 1200 bps. Any other line speed will use a CCITT modulation standard. The parameter value, if valid, is written to S27 bit 6.

Syntax

B<value>

Defined Values

<value> Decimal number corresponding to the selected option.

0

Selects CCITT operation at 300 or 1200 bps during Call Establishment and a subsequent connection. (Default.)

1
Selects BELL operation at 300 or 1200 bps during Call Establishment and a subsequent connection.

Result Codes

OK

<value> = 0 or 1

ERROR

Otherwise