Multi-Tech Systems MT5600DSVD User Manual

Page 38

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MultiModemDSVD User Guide

4 AT Commands, S-Registers, and Result Codes

33

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:

%C

n 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.

Command:

%E

n 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.

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