si2439-a-gm Silicon Laboratories, si2439-a-gm Datasheet - Page 22

• Manufacturer Part Number: si2439-a-gm
• Description: V.92 And V.34 Isomodem With Global Daa
• Manufacturer: Silicon Laboratories

Si2494/39
4.12. V.92 PCM Upstream
The Si2494/39 supports the ITU-V.92 PCM upstream data protocol. This protocol allows the ISOmodem to connect
at speed up to 48 kbps upstream. Previously the upstream connection rate was limited to 33.6 kbps. The PCM
upstream mode is enabled by default; to disable, issue the AT command +PIG = 1 (see Table 10 on page 27). To
view both downstream and upstream connect speeds in the connect result message, issue the command “AT \V4”
or “AT+MR”.
4.13. V.92 Quick Connect
The Si2494/39 supports the ITU-V.92 quick connect protocol. Quick connect enables the modem to save and reuse
line condition parameters to reduce startup negotiation time.
The quick connect feature is enabled by default in the Si2494/39. For information on changing the quick connect
settings, see the +PSS and +PQC commands shown in Table 10 on page 27.
4.14. V.92 Modem-on-Hold
The modem-on-hold (MOH) feature allows the modem user to answer an incoming call while connected online
without dropping the internet connection. The modem will remain “on hold” for a period of time determined by the
host and the ISP. There are four AT commands that control the operation of MOH. The commands are as follows:
+PCW, +PMH, +PMHT, +PMHR. By changing these parameters, the user can enable/disable call waiting and
MOH, set the MOH request timeout, and set the MOH initiate timeout. For further details and syntax on these
commands see Table 10 on page 27. The MOH feature is most useful when the Si2494/39 is connected to a
central office that allows call waiting.
22
Caller Id Report
Distinctive Ringing
RING
DTMF Received
Facsimile Calling (e.g. 1100 Hz)
Data Calling (e.g. 1300 Hz)
Presumed End of Message (QUIET) Time-out
Loop Current Interruption
Ringing Tone
BUSY
DIALTONE
Extension Phone On-hook
Extension Phone Off-hook
Facsimile or Data Answer (e.g. 2100 Hz)
Data Answer (e.g. 2225 Hz)
Event Description
Table 9. V.253 Event Reporting in Voice Mode
Rev. 1.0
1-9,A-D,*,#
Reporting
Complex
Complex
R
P
c
e
q
b
d
p
a
r
f
l
0,1,4,5,20,21
0,1,4,5,20,21
0,4,20,21
0,4,20,21
0,4,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
1,5,20,21
+VLS