Dial up Modem programming

MrBlobby · 27 Jun 2013 at 17:38

How do I program my dial up modem to make a phone call. I want it to maintain a connection to a phone number like dialup internet but to a number that isn't an internet dial up network.

Thanks

Evilpaul · 27 Jun 2013 at 20:09

Nearly all MODEMs (including the data connections in modern smartphones) use extensions of the AT command set. You'll need to use some API to send the correct sequence of AT commands to your MODEM.

After having to do some of this at work, all I can say is good luck!

!bluetonic! · 1 Jul 2013 at 10:47

This is intriguing. Can you tell us more?

Is there not a more modern tech that can help you? VPN, SIP, IM?

Chaos · 1 Jul 2013 at 11:30

Maybe you could set up a BBS on the other number.

http://lunduke.com/?p=2156

d_brennen · 1 Jul 2013 at 11:36

IIRC this can be done with Hyperterminal and the AT command set, but it's been a loooong time since I messed with modem telephony

RobH · 1 Jul 2013 at 21:06

Something like WVDial on Linux and a USB or Serial model will do what you want, it's really easy to setup and you can just give it a number to dial.

MrBlobby · 1 Jul 2013 at 21:30

RobH said:
Something like WVDial on Linux and a USB or Serial model will do what you want, it's really easy to setup and you can just give it a number to dial.

Thanks can I set the length of phone call ? and also can it deffo connect to non ISP number.

Strikeforce · 3 Jul 2013 at 21:25

You could always just send AT commands to the COM port that the modem is assigned to.

topbanana · 4 Jul 2013 at 13:41

It used to be ATDT (attention, dial, tones), but I don't know how to stop it trying to negotiate with the other end.

MrBlobby · 12 Jul 2013 at 15:38

Strikeforce said:
You could always just send AT commands to the COM port that the modem is assigned to.

Thanks, how do I do that ? I've no idea !

Confused · 12 Jul 2013 at 16:39

Open COM X, send the following command:

Code:

ATD 01234567890;

This will dial, and the ";" will return you to Command mode, rather than trying to handshake.

Then, when you need to, send the following command to hang up.:

Code:

ATH

It's been quite a while since I did anything with AT commands (and I was doing it to a T68i mobile phone hooked up via a serial connection...), so this is mostly from memory plus a little google to help (I didn't know about the ; option before today, but knew about ATDT and ATH)

MrBlobby · 12 Jul 2013 at 17:53

Thanks how do I open COM X ? sorry for being dim

Confused · 15 Jul 2013 at 13:34

I spent a little while last night putting together a little app for this for you in Visual Basic 6 - because I was bored

I've put the full source code, plus the executable, on my github.

I've not tested it with a modem, but I have hooked up a virtual COM port, and logged that it sends the commands out - what happens with a real modem though, I don't know.

I have included some OCX files in case your PC doesn't have them.

Hopefully it's straight forward enough to understand...

MrBlobby · 15 Jul 2013 at 14:55

Hey thanks Mr Confused big up to boredom

Confused · 18 Jul 2013 at 14:26

Did you get a chance to test it out?

MrBlobby · 19 Jul 2013 at 09:13

Sorry not yet I'll have to get a modem

Thanks for the help

Confused · 19 Jul 2013 at 11:18

No worries - I've subscribed to the thread anyway, so when you do get a chance to test, just reply and I'll be notified