Chapter 2 - AT Commands, S-Registers, and Result Codes

 

 

 

Command:

Sr?

Read Register Value

Values:

 

r = S-register number

Default:

 

None

Description:

 

Read value of register Sr and display it in 3-digit decimal form. E.g., S2? gives the response 043.

Command:

T

Tone Dialing

Values:

 

P, T

Default:

 

T

Description:

 

Configures the modem for DTMF (touch-tone) dialing. Dialed digits are tone dialed until a P

 

 

command or dial modifier is received.

Command:

Vn

Result Code Format

Values:

 

n = 0 or 1

Default:

 

1

Description:

V0

Displays result codes as digits (terse response).

 

V1

Displays result codes as words (verbose response).

Command:

Wn

Result Code Options

Values:

 

n = 0, 1, or 2

Default:

 

2

Description: W0 CONNECT result code reports serial port speed, disables protocol result codes.

 

W1

CONNECT result code reports serial port speed, enables protocol result codes.

 

W2

CONNECT result code reports line speed, enables protocol result codes.

Command:

Xn

Result Code Selection

Values:

 

n = 0–7

Default:

 

4

Description:

X0

Basic result codes (e.g., CONNECT); does not look for dial tone or busy signal.

 

X1

Extended result codes (e.g., CONNECT 46000 V42bis); does not look for dial tone or busy signal.

 

X2

Extended result codes with NO DIALTONE; does not look for busy signal.

 

X3

Extended result codes with BUSY; does not look for dial tone.

 

X4

Extended result codes with NO DIALTONE and BUSY.

 

X5

Extended result codes with NO DIALTONE and BUSY.

 

X6

Extended result codes with NO DIALTONE and BUSY.

 

X7

Basic result codes with NO DIALTONE and BUSY.

Command:

Zn

Modem Reset

Values:

 

n = 0 or 1

Default:

 

None

Description:

Z0

Reset modem to profile saved by the last &W command.

 

Z1

Same as Z0.

Command:

&Cn

Data Carrier Detect (DCD) Control

Values:

 

n = 0 or 1

Default:

 

1

Description:

&C0

Forces the DCD circuit to be always high.

 

&C1

DCD goes high when the remote modem’s carrier signal is detected, and goes low when the

 

 

carrier signal is not detected.

Command:

&Dn

Data Terminal Ready (DTR) Control

Values:

 

n = 0, 1, 2, or 3

Default:

 

2

Description:

&D0

Modem ignores the true status of the DTR signal and responds as if it is always on.

 

&D1

If DTR drops while in online data mode, the modem enters command mode, issues an OK, and

 

 

remains connected.

 

&D2

If DTR drops while in online data mode, the modem hangs up. If the signal is not present, the

 

 

modem will not answer or dial.

 

&D3

If DTR drops, the modem hangs up and resets as if an ATZ command were issued.

MT3334SMI

23

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Multi-Tech Systems MT3334SMI Sr? Read Register Value, Tone Dialing, Result Code Format, Result Code Options, Modem Reset