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FabB
Tl Posts:
5

France
Posted - 3/2/2004 2:36:03 AM  Show Profile  Email Poster  Edit Message
Hi,

I would like to configure my LT WinModem to communicate with a SMS-Center (fixed line SMS) at V23 half duplex.
But I don't know which configuration is required for my modem. Could you help me ?

charles
Tl Posts:
5879

USA
Posted - 3/2/2004 8:41:19 AM  Show Profile  Email Poster  Edit Message
Use +MS=V23 in extra settings.
What driver version are you using.
http://www.modemsite.com/56k/x2-linklimit.asp#Lucent
FabB
Tl Posts:
5

France
Posted - 3/3/2004 4:37:46 AM  Show Profile  Email Poster  Edit Message
I tried AT+MS=V23 but it did'nt work.
I think it's because it's half duplex and my modem has to be connected immediatly to receive data transmitted by SMS-Center.
FabB
Tl Posts:
5

France
Posted - 3/3/2004 4:38:20 AM  Show Profile  Email Poster  Edit Message
I tried AT+MS=V23 but it did'nt work.
I think it's because it's half duplex and my modem has to be connected immediatly to receive data transmitted by SMS-Center.
v.Richard
Tl Posts:
6222

USA
Posted - 3/3/2004 12:49:19 PM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
http://www.arcelect.com/V23_modem_modulation_Explained.htm

The V.23 specification is for a Dial or leased line modem operating at 600/1200 bps over 2 wires in one direction. It has a backward channel of up to 75 bps for error control.

The mark space frequencies are close enough that many 202T modems can communicate with V.23 modems. Many times V.23 is mistakenly used to identify a 0/1200 bps modem in applications outside the U.S. V.23 is NOT 1200 bps in both directions.

The only time a V.23 modem is needed is to connect to an existing true V.23 modem,

Or an application where the same modem type must do both dial and leased line operation. There are very few TRUE V.23 modems.


----
How are you trying to connect?
I would suggest - Hyperterminal connected directly to modem COM port
www.modemsite.com/56k/x2-hyperterm.asp

Then, give modem
AT&F
AT+MS=V23,0 (or V23C,0)
then dial in -
do you get connect? data?

If not,
same, but before dialing, disable compression & error correction (see command reference -
http://www.agere.com/client/docs/v90atcom.pdf )

The half-duplex is only related to the modem-modem link. Your PC->modem via the virtual COM port is irrelevant and will always be 'full-duplex'.

Aloha! Richard.

Edited by - v.Richard on 3/3/2004 12:51:21 PM
Edited by - v.Richard on 3/3/2004 8:43:09 PM

FabB
Tl Posts:
5

France
Posted - 3/4/2004 4:17:37 AM  Show Profile  Email Poster  Edit Message
Thanks for your answer,
Unfortunately that doesn't work.
Here a quick description taken from 'ETSI ES 201 912 V1.1.1' :

"Every signalling between the SM-TE and the SM-SC is carried out in the voice band using a bi-directional, half duplex 1 200 Baud FSK modulation. The Physical Layer requirements are described in EN 300 659-2 [7] for the FSK
transmission function and EN 300 778-2 [10] for the FSK receiving function.
The entity which answers an incoming call shall send the first FSK-frame to the entity which initiated the call.
After the call has been established by the SM-TE and answered by the SM-SC, the first FSK frame (an SMS connection
establish message) is sent out from the SM-SC to the SM-TE. The SM-TE responds with a second FSK frame which
carries the SM data.
Due to the used half duplex communication via a network in which echo-suppressors or echo-cancellers may be active,
a minimum delay time between two successive FSK frames of 100 ms."
If I tried a command ATD my modem is never connected.
The modem has to be connected IMMEDIATLY after dialing.
I think, it's not possible with my Lucent Modem.

Fabrice

v.Richard
Tl Posts:
6222

USA
Posted - 3/12/2004 9:19:17 AM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
I don't think the description you've given describes a V.23 call -
V.23 provides a uni-directional half-duplex link - your material describes a bi-directional half-duplex link.

I don't think there's a modem standard that covers the link you want to do - which would mean you need 'proprietary' modem designed to work with the other end.

Aloha! Richard.

FabB
Tl Posts:
5

France
Posted - 3/17/2004 7:27:10 AM  Show Profile  Email Poster  Edit Message

DO you know any modem to avoid V25 connection phase ?
The lucent modem has the V23 half duplex 1200 bauds mode but, my modem can connect to the SMS Center.
The modem has to be connected immediatly after dialing or responding to transmit or receivre an SMS_ESTABLISHMENT frame.
Actually, the modem has to be connected immediatly after dialing, is it possible to do that with a lucent modem, or any other modem ?
zell
Tl Posts:
2

Singapore
Posted - 4/28/2004 8:14:10 PM  Show Profile  Email Poster  Edit Message
Hi, I'm actually trying to find out whether normal modems can be used to send fixed line sms. Can any one enlighten on that ?
zell
Tl Posts:
2

Singapore
Posted - 4/28/2004 8:14:25 PM  Show Profile  Email Poster  Edit Message
Hi, I'm actually trying to find out whether normal modems can be used to send fixed line sms. Can any one enlighten on that ?
touchring
Tl Posts:
2

Singapore
Posted - 5/15/2004 8:48:01 AM  Show Profile  Email Poster  Edit Message
Hi Richard,

You mentioned proprietary modems, what are the V.23 proprietary modems available and which you would recommend.

Is Microsol's DM-16 is good selection? http://www.arcelect.com/V23_Modem-DM16.htm

sms paul
Tl Posts:
1

United Kingdom
Posted - 12/8/2004 10:50:03 AM  Show Profile  Email Poster  Edit Message  sms pauls Homepage
You may wish to consider a modem designed for landline SMS, you will find what you want at www.z-text.com the AT command set is documented in the technical section

Landline SMS via a PC
Landline SMS Modem with AT command set
www.z-text.com

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