Rockwell RCV144ACx, Command Reference Manual

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AT Command Reference Manual
1048 3-55
Example 3: Switch from normal handset conversation to AudioSpan data connection between two RCV288 modems in
normal (non-error corrected) mode. Headset operation will be selected on the originate modem and speakerphone operation
will be selected on the answer modem as the audio interface during AudioSpan connection. The originate DTE prefers a
ML288/14400 connection for good audio quality and does not require high throughput. Both DTEs are set at 57600 bps:
Originate Modem Answer Modem
DTE DCE DTE DCE Comments
User’s establish handset
conversation and both handsets
are off-hook.
AT&F\N0 AT&F Reset modems. Normal mode
operation is selected by originate
DTE.
OK OK
AT#VLS=5 AT#VLS=6 Handset mode selected for
originate mode. Speakerphone
mode selected for answer
modem.
OK OK
AT-SMS= 2,
14400 ,14400 AT-SMS=2 Enable AudioSpan. Originate DTE
wishes to force a ML288/14400
with audio connection.
OK OK
ATD Originate modem initiates data
negotiation but will not actually
dial since the handset is already
offhook.
RING Answer modem detects
negotiation sequence and reports
RING message to DTE.
ATA DTE responds to RING by
answering.
CONNECT 57600 CONNECT 57600 AudioSpan is established and
user’s can resume conversation.
The connect message represents
the DTE speed on each side.
<data> <data> Modems exchange data.
+++ Answer modem enters command
mode to prepare for disconnect.
OK
ATH
NO CARRIER NO CARRIER Modems disconnect in AudioSpan
mode but handsets are still
offhook and conversation can
continue. Conversation is
terminated when both handsets
are hung up.
Note: The transition from handset conversation to AudioSpan mode can take up to 8 seconds. The handsets will be silenced
during the negotiation period.