MultiModemDSVD User Guide

 

4 AT Commands, S-Registers, and Result Codes

Command:

&Zy=x

 

Store Telephone Number

Values:

 

 

y = 0–3

 

 

 

x = Dialing command

Default:

 

None

Description:

 

 

Stores telephone dial string x in memory location y. Each tele-

 

 

 

phone number dial string can contain up to 34 digits. Dial the

 

 

 

stored number using the command ATDS=y.

 

 

 

 

 

 

 

Note: DTR dialing uses the number stored in memory location 0.

 

 

 

 

Command:

%Cn

 

Data Compression Control

Values:

 

 

n = 0, 1, 2, or 3

Default:

 

3

Description:

 

 

Enables or disables data compression negotiation. The modem

 

 

 

can only perform data compression on an error-corrected link.

 

%C0

 

Disables data compression.

 

%C1

 

Enables MNP 5 data compression negotiation.

 

%C2

 

Enables V.42bis data compression negotiation.

 

%C3

 

Enables both V.42bis and MNP 5 data compression negotiation.

 

 

 

 

 

 

 

Note: This command controls both V.42bis and MNP-5 data

 

 

 

compression, whereas the &E14 and &E15 commands control

 

 

 

only V.42bis data compression. The command in effect is the

 

 

 

one last entered.

 

%En

 

 

Command:

 

Line Quality Monitor

Values:

 

 

n = 0, 1, or 2

Default:

 

2

Description:

 

 

Controls whether or not the modem will automatically moni-

 

 

 

tor the line quality and request a retrain (%E1) or fall back to a

 

 

 

lower speed when line quality is insufficient and fall forward

 

 

 

to a faster speed when line quality is sufficient (%E2).

 

%E0

Disable line quality monitor and auto-retrain.

 

%E1

Enable line quality monitor and auto-retrain.

 

%E2

 

Enable line quality monitor and fallback/fall forward.

Command:

%L

 

Line Signal Level

Values:

 

 

None

Default:

 

 

None

Description:

%L

 

Returns a value that indicates the received signal level. The

 

 

 

value returned is a direct indication (DAA-dependent) of the

 

 

 

receive level at the MDP, not at the telephone line connector.

 

 

 

For example, 009 = -9 dBm, 043 = -43 dBm, and so on.

Command:

%Q

 

Line Signal Quality

Values:

 

 

None

Default:

 

 

None

Description:

%Q

 

Reports the line signal quality (DAA-dependent) as a three-

 

 

 

digit number. Returns the higher order byte of the EQM value.

Based on the EQM value, retrain or fallback/fall forward may be initiated if enabled by %E1 or %E2.

Multi-Tech Systems, Inc.

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