Q:
What is the difference between a regular modem chipset and the C54CST chip?
A:
A regular modem chipset is usually a closed system, and the developer has to
add a host processor in order to control this chip. Besides, very few things
can be customized inside the modem chipset. Unlike a regular modem, the CST
chip is very customizable and the user can add his/her own software,
including modem control software, as well as design a complete system just
based on this chip. The table below illustrates the difference (the
functional features of CS are compared with features of two other modems).
Q:
Can I work with the data pump directly? If yes, do I need the modem routines
used in the file DMController.c?
A:
If you wish to work with the data pump directly, you can do without Modem
Integrator and DMController. However, we would advise you to use them, and to
operate the modem via DMController. That way you will be able to use V.42 and
V.42bis, and have some useful control logic above pure data pump. The DMController.c, CSTService.c and ATParser.c (call-back function) files contain examples of how to
handle the modem data transfer.
Q:
Can I detect the FAX tone using CST?
A:
Fax functionality is not included in the standard CST SDK delivery, although
it can be included as an add-on. Concerning the CED/CNG detection, CST
includes a Universal Multiple Tone Detector (UMTD), which can be configured
to detect any groups of tone (e.g. DTMF, Call Progress Tones, etc). However,
it is not a full fax detector (e.g., the V.21 detection is unavailable). We
recommend you to implement a custom fax detection algorithm, and then add it
to CST services.
Q:
I have done a few basic tests with the C54CST and C54v90 solution, and
encountered the following problem. With the default configuration of the
modems, when the caller is a V.90 modem, the connection is established
according to the V.32bis protocol and works correctly. When the caller is the
CST modem, the connection speed is 2400 and weird characters appear.
A:
To handle this problem, use the patch included in the SDK (see "CST2 SDK
Release Notes").
Q:
Can we avoid using the V.14 protocol while working with CST?
A:
V.14 is controlled by the Modem Integrator algorithm. To avoid using it, you
should work with the modem directly via the Data Pump algorithm, without
accessing the Framework functions at all.
Q:
Is it possible to accelerate the connection for the CST modem?
A:
You can connect the modem in the ITU compatible fast connect mode which can
be set via S-register S29 or by the AT command AT#F; see section 9.3.3.15 of
"CST User's Guide" (literature number SPRU029). In this mode the
modem will not transmit, nor will it wait for the Answer tone (2100 Hz tone
in the beginning of modem connection), and the training time for V.32bis/V.32
modem echo canceller will be reduced to a minimum (0.5 sec).
Q:
Does Spirit Corp. have (perhaps as an add-on) either a V.22 fast connect or a
V.29 fast connect?
A:
Yes, we have an available add-on with the following features:
-V.29 fast (quick) connect (ITU compatible). Both originate and response
modes. Both standard and alternate startup.
-V.22 1200 fast (quick) connect (non ITU compatible). Both originate and
response modes.
All protocols are implemented in compliance with those supported by Hypercom.
But the question about the name of this specification is unclear, since it is
not published officially. Moreover, Conexant offers a chip with V.22 2400
quick connect mode only, which appears incompatible with our and Hypercom's
quick connect.
Q:
What additional features does the 54CST chip have as compared with a regular
modem with voice features?
A:
Most voice modems support only half-duplex voice transfer, like voice play
out or voice recording, whereas CST voice features include full-duplex voice
transmission. Another feature of CST solution that distinguishes it among
other modems is line echo canceller which suppresses line echo arising when a
signal is passed from a double line to four-wire line and vice versa.
Q:
Can I work with the data pump directly? If yes, do I need the modem routines,
which are used in the file dmcontroller.c?
A:
If you want to work with data pump directly, you can go without Modem
integrator and DMController. But, we would advise you to use them, and to
operate the modem via DMController. That way you will be able to use V.42 and
V.42bis, and have some useful control logic above pure data pump. The DMController.c, CSTService.c and ATParser.c (call-back function) files contain
examples of how to handle modem data transfer.
Q:
I have a design that requires v90 application. I bought the TMS320C54v90 chip
from Spectrum Digital to help with this process. The only problem is the
TMS320C54v90 chip doesn't offer a flex mode (or does it? (like the C54CST
chip)). Is it possible to load CST code on the DSP of the C54v90 to get this
application to work?
A:
C54V90 chip does not have an open architecture, and does not allow to create
flex applications on top of its algorithms (there is an awkward way to do
some simple flex applications in it, but PCTel discloses the information on
it only to certain clients).The code written for C54CST is not compatible
with C54V90.
Q:
Can I detect the FAX tone using CST?
A:
Fax functionality is not included in the standard CST SDK delivery. Still it
can be included as an add-on. Concerning CED/CNG detection, CST includes a
Universal Multiple Tone Detector (UMTD), which you can configure to detect
any groups of tone (e.g. DTMF, Call Progress Tones etc). However it is not a
full fax detector (e.g. V.21 detection is not available). We recommend you to
implement your own fax detection algorithm by yourself and then add it to CST
services.
Q:
I have done few basic tests with the C54CST and C54V90 solution and met the
following problem. With the default configuration of the modems, when the
caller is the V90 modem, the connection is established of the V32bis protocol
and it works correctly. When the caller is the CST modem, the connection
speed is 2400 and weird characters appear.
A:
To handle this problem use the patch included in the SDK (see "CST2 SDK
Release Notes").
Q:
Can we avoid using the V.14 protocol working with CST.
A:
V.14 is controlled by Modem Integrator. To avoid using it you should work
directly with Data Pump without using Framework functions for work with the
modem.
Q:
Is it possible to accelerate the connection time for the CST modem?
A:
You can connect the modem in the ITU compatible fast connect mode which can
be set via S-register S29 or by the AT command AT#F, see section 9.3.3.15 of
"CST User's Guide" (literature number SPRU029). In this mode the
modem will not transmit nor will it wait for the Answer tone (2100 Hz tone in
the beginning of modem connection), and the training time for V.32bis/V.32
modem echo canceller will be reduced to minimum (0.5 sec).
Q:
Does SPIRIT. have (perhaps as an add-on) either V.22 fast connect or V.29
fast connect?
A:
Yes, we have available add-on with the following features:
- V.29 fast (quick) connect (ITU compatible). Both originate and response
modes. Both standard and alternate startup.
- V.22 1200 fast (quick) connect (non ITU compatible). Both originate and
response modes.
All protocols are implemented in compliance with those, supported by
Hypercom. But the question about the name of this specification is unclear,
since it is not published officially. Moreover, Conexant offers a chip with
the only V.22 2400 quick connect mode, that seems incompatible with our and
Hypercom's quick connect.
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