Multi-Tech Systems MT2456SMI22 User Manual

Page 22

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Chapter 4 - V.22bis Commands

Multi-Tech Systems, Inc. MT2456SMI-22 SocketModem Developer’s Guide

22

T

Set Tone Dial Default

This command forces DTMF dialing until the next P dial modifier or P command is received. The modem will set an
S-Parameter bit to indicate that all subsequent dialing should be conducted in tone mode. The DP command will
override this command. Clears S14 bit 5. This command may not be permitted in some countries. (See P.)
Result Code

OK

P

Set Pulse Dial Default

This command forces pulse dialing until the next T dial modifier or T command is received. Sets S14 bit 5.
As soon as a dial command is executed which explicitly specifies the dialing mod e for that particular call (e.g.;
ATDT), this command is overridden so that all future dialing will be tone dialed. (See T command.)
This command may not be permitted in some countries.
Result Code

OK

A

Answer

The modem will go off-hook and attempt to answer an incoming call if correct conditions are met. Upon successful
completion of answer handshake, the modem will go on-line in answer mode. This command may be affected by the
state of Line Current Sense, if enabled. (Most countries do not require Line Current Sense.) Operation is also
dependent upon country-specific requirements.
The modem will enter the connect state after exchanging carrier with the remote modem.
If no carrier is detected within a period specified in register S7, the modem hangs up.
Any character entered during the connect sequence will abort the connection attempt.

H

Disconnect (Hang-Up)

This command initiates a hang up sequence. It may not be available for some countries due to PTT restrictions.
Syntax H<value>
Defined Values
<value> Decimal number corresponding to the selected option.
0

The modem will release the line if the modem is currently on-line, and will terminate any test (AT&T) that is in
progress. Country specific, modulation specific, and error correction protocol specific (S38) processing is
handled outside of the H0 command.

1

If on-hook, the modem will go off-hook and enter command mode. For U.S., the modem will remain off-hook. For
other countries, the modem will return on-hook after a period of time determined by S7.

Result Codes

OK <value> = 0 or 1.
ERROR Otherwise.

O

Return to On-Line Data Mode

This command determines how the modem will enter the on-line data mode. If in the online command mode, the
modem enters the on-line data mode with or without a retrain. If in the off-line command mode (no connection), the
modem reports ERROR.
Syntax O<value>
Defined Values
<value> Decimal number corresponding to the selected option.
0

Enters on-line data mode without a retrain. Handling is determined by the Call Establishment task. Generally, if a
connection exists, this command connects the DTE back to the remote modem after an escape (+++).

1

Enters on-line data mode with a retrain before returning to on-line data mode.

Result Codes

OK <value> = 0 to 1 and a connection exists
ERROR Otherwise, or if not connected

L

Speaker Volume

This command sets the speaker volume control. The parameter value, if valid, is written to S22 bits 0 and 1.
Syntax L<value>
Defined Values
<value> Decimal number corresponding to the selected option.
0

Low volume.

1

Low volume. (Default)

2 Medium

volume.

3 High

volume.

Result Codes

OK <value> = 0 to 3
ERROR Otherwise

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