AT Commands, S-Registers, and Result Codes

Displaying a Stored Number

To display a stored telephone number, type &Zn? in terminal mode, where n is the memory register in which the number is stored. For example, type AT&Z5? <cr> to display the telephone number in memory register 5. To list all ten telephone numbers stored in memory, type ATL <cr>.

Answering a Call

You can answer incoming calls to the MTA128ST/NT either manually or automatically. When the TA detects an incoming call, it turns on the RI signal on the V.24 interface and sends a RING result code to the computer or terminal after each ring. If autoanswer is enabled, the TA automatically answers the call. You can manually answer the call with the A command. Both methods are described below.

Answering Manually

If your communication program is in terminal mode when the RING result code appears on your monitor, you can manually answer the call by typing ATA <cr>.

Answering Automatically

To cause the MTA128ST/NT to automatically answer a call:

1.Enable autoanswer by setting register S0 to the ring on which you want the TA to answer (e.g., in terminal mode, type S0=4 to make the TA answer on the fourth ring). You also can use either of the configuration utilities to the turn on autoanswer and set the number of rings.

2.Make sure that the TA is offline.

The TA answers the call after the number of rings specified by S0. To disable autoanswer, use a configuration utility or the command S0=0.

Note: If the user wants to accept calls while DTR is low, the TA must be configured to ignore DTR. To do this, enter AT&D0<cr>. With this configuration, the TA can accept calls while DTR is low. If this configuration setting is not made, the TA rejects incoming calls until DTR is high while calls comes in.

Hanging Up

To hang up a call, escape to online command mode (+++AT<cr>), then enter the H command

(ATH<cr>). The escape sequence and hang up command can be combined into one command string:

+++ATH<cr>.

MTA128ST/NT

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