Ericsson T39 - Using the Call List

AT Commands 10
The following illustration summarises the methods that are used to switch between the three built-in modem
operating modes:
3.3.1 Operating in off-line command mode
In off-line command mode, the built-in modem accepts data as commands and not as normal communication
traffic. You enter commands by typing at the PC/PDA keyboard.
Switching to on-line data mode
To enter on-line data mode, for data to be exchanged with the modem at the other end of the link, enter the
ATD command followed by the telephone number to make the call. Alternatively, typing ATA to answer an
incoming call will also place the built-in modem in on-line mode.
Switching back to off-line command mode
Any of the following will return the built-in modem to off-line command mode from on-line data mode:
• Loss of the connection (NO CARRIER error)
• Loss of the infrared link between the built-in modem and your computer
• Pressing the “NO” button on your mobile phone
3.3 Changing the built-in modem operating mode
Power up
Off-line Command Mode
On-line Command Mode
On-line Data Mode
Exchange AT command data between computer and
Built-in Modem
Exchange data or facsimile
with a remote modem
Exchange AT command data with the Built-in
Modem while staying on-line
Lose carrier
or
lose I.R.
link
or
press “NO”
button
(or
pull DTR
low
*)
Lose carrier
or
lose I.R. link
or
press “No”
button
(or pull DTR
low
*) or ATH
+++AT <?>
(or pull DTR
low
*)
Answer
ATA
ATO
Dial
ATD
<tel.no.>
* Pull DTR not available
when using cable.