AT Commands, S-Registers, and Result Codes

Result Codes

When the MTA128ST/NT receives an AT command from the computer or terminal, it attempts to execute the command, then sends a status message to the computer or terminal that reports the result of the command. The MTA128ST/NT provides you with several of these response messages, or result codes, which can be displayed on your monitor or intercepted and used by your communications software. Using the V command, you can select whether the result codes are terse (numbers) or verbose (words).

The MTA128ST/NT’s result codes are listed below. Note that the speed of an ISDN channel is always either 56 Kbps or 64 Kbps. Connect messages indicate the speed of the connection between the MTA128ST/NT and your computer or terminal.

TERSE VERBOSE

DEFINITION

 

0

OK

TA executed the command without error

1

CONNECT

TA established an ISDN connection

2

RING

TA detected a ring caused by incoming call

3

NO CARRIER

TA did not detect carrier within time allotted by register

 

 

S7

4

ERROR

Error in the AT command

5

CONNECT 1200

TA connected at 1200 bps

6

NO DIALTONE

TA has a poor connection to ISDN network

7

BUSY

TA detected a busy signal

8

CONNECT 300

TA connected at 300 bps

9

CONNECT 600

TA connected at 600 bps

10

CONNECT 2400

TA connected at 2400 bps

11

CONNECT 4800

TA connected at 4800 bps

12

CONNECT 9600

TA connected at 9600 bps

14

CONNECT 19200

TA connected at 19200 bps

17

CONNECT 56000

TA connected at 56000 bps

18

CONNECT 57600

TA connected at 57600 bps

19

CONNECT 64000

TA connected at 64000 bps

28

CONNECT 38400

TA connected at 38400 bps

79

PPPC PROTOCOL

TA using Point-to-Point protocol

80

HDLC PROTOCOL

TA using raw HDLC mode

82

V.110 PROTOCOL

TA using V.110 rate adaption protocol (Note: V.110 is

 

 

supported on some MTA128ST models only.)

83

V.120 PROTOCOL

TA using V.120 rate adaption protocol

84

X.75 PROTOCOL

TA using X.75 rate adaption protocol

87

CLEAR PROTOCOL

TA using CLEAR (transparent) protocol

Using AT Commands to Operate the MTA128ST/NT

You can configure and operate the MTA128ST/NT entirely with AT commands if you like. But remember, you can issue AT commands only from a terminal or from a computer running a communications program in terminal mode. This section describes how to use AT commands for basic operations, such as calling, answering a call, and hanging up.

Modes of Operation

The MTA128ST/NT has three modes of operation. They are:

•Offline Command Mode—MTA128ST/NT communicates with the terminal or computer and responds to AT commands. There is no data communications link with a remote device.

MTA128ST/NT

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