Silicon Laboratories SI2493/57/34/15/04 - Manual (Page 201)

AN93
Rev. 1.3 201
7.6. Telephone Answering Machine
7.6.1. Overview
The Si2494/39 supports telephone answering machine (TAM) operations. These parts use the V.253 command set
to control operation. This section covers the three major TAM-related system voice modes. Some modes offer
multiple operations.
The TAM Hands-Free mode is the general voice idle mode. It is used for OGM recording/review and local ICM
recording/review via hands-free operation. The TAM Handset mode is similar to TAM Hands-Free except that the
audio is handled over the handset. The TAM PSTN mode is for playback of the OGM and recording the ICM. The
TAM PSTN mode also permits remote OGM and ICM record/review via DTMF tone control. The +VTX command is
used to play voice menu options/prompts. All the use cases in this section start with the modem in TAM
Hands-Free mode, which is configured in the initialization sequence in Table 119 on page 194.
7.6.2. TAM Hands-Free—Idle
The modem will use the events listed in Table 112 on page 179 to communicate status. The <DLE><R> event
indicates ring detection. The +VTS command can be used to play one or more single/dual tone sequences. If
enabled, Type I CID is decoded after the first ring and sent via a complex <DLE> event report. See Table 126 for
details.
Based upon the TAM answer function settings, a ring counter will validate the number of rings before answer. If the
TAM Answer function is disabled or the number of rings before answer has not been reached, the user has the
opportunity to answer the call via handset or speakerphone.
Table 126. Local Ring Notification with Type I CID Event
Host to Modem Commands / Data
Modem to Host Result
Codes/Data
Local Modem Actions
<DLE><R> Ring Detection
AT+VTS=[700,500,80] OK Play local ring tone.
<DLE><X>
CIDM
DATE=0101
TIME=0110
NMBR=102
NAME=JONES JENNIFER
<DLE><.>
Receive Type I CID DLE complex report.
<DLE><R> Ring Detection.
AT+VTS=[700,500,80] OK Play local ring tone.
<DLE><R>
Ring Detection. The voice driver will use a
rings-to-answer count. This example uses
three rings before answer.
AT+VTS=[700,500,80] OK Play local ring tone.