Problem with Modem communication:

[vgonepudi]

Hi,

Requirement: I want to send numeric message to pager.

For that I have developed an application in VC++. My application takes pager number as input and dials that number through my local modem. After establishing the connection I am getting a message like “Enter numeric message after beep”.

How can I find whether connection is established or not?

I tried to read “CONNECT” message but I am not getting that message.

After establishing the connection how can I send numeric message?

I know after establishing the connection mode will goes to command mode and we can send any data. But I don’t know how to send data in C++.

I used ATDT and number for dialing modem.

If any body knows about how to fix this one please let me know.

Thanks

 

[John Lewis]

You will never receive the "CONNECT" message because you are not technically "connecting" to a modem. You are connecting to a device that listens for DTFM tones, the same tones that are used for dialing.

If you are using a voice capable modem, you should in theory be able to listen for the beep that signals the device is ready for the message, but that solution would be rather complicated. Generally, waiting for a fixed amount of time before sending the message data will be sufficient, although you will not be able to verify that the page was sent.

Sending the page is simply. Since the device you are connecting to is expecting DTFM, use ATDT to dial the appropriate numbers.

A better solution would be to dial a pager terminal. Pager terminals are modems that are setup to accept numeric or text pages, generally using the TAP protocol. Notepager is a commercial product that does this (

http://www.notepager.com/),

HylaFax also has a TAP protocol implementation (

http://www.hylafax.org).

 

[edfair]

IF you are using a "HAYES" command set modem and you have it set up correctly you will receive a connect message indicating that you have "VOICE".
This is the X4 portion of the command set. I don't know what the results are but suspect that they go off-hook immediately unless you override the the handshake signals that are required to maintain communications.
I know there are signs in airports that get updated text messaging through pager systems via modem so it is possible.


Ed Fair
Give the wrong symptoms, get the wrong solutions.