Receiving data via modem
Receiving data via modem
(OP)
Hello -- I'm working on a project where I can call my home phone number, and after 5 rings my home PC "picks up" via a modem. Then, I want to be able to enter in a series of numerical codes to change things on my PC. I'm at the point where, using VB and Hayes-compatible codes, I can call my phone and the the modem picks up. I'm using a standard external modem w/ 9600 baud serial to my Com port. But, if I punch in a few numbers, I can't get the modem to send data back to the PC (I can hear the DTMF and my voice through the modem speaker).
My question is: does a modem translate standard numerical incoming DTMF signals into ascii serial bytes that I can detect through the Com port? If not, can anyone suggest a way to do this (without having to design my own circuit)? Also, what type of handshaking has to occur in order to send out DTMF tones back to the incoming phone call (just to audibly verify certain steps in the VB app)? Thanks for anyone that can give me a quick lesson in modem protocol!
My question is: does a modem translate standard numerical incoming DTMF signals into ascii serial bytes that I can detect through the Com port? If not, can anyone suggest a way to do this (without having to design my own circuit)? Also, what type of handshaking has to occur in order to send out DTMF tones back to the incoming phone call (just to audibly verify certain steps in the VB app)? Thanks for anyone that can give me a quick lesson in modem protocol!





RE: Receiving data via modem
http://www.claremicronix.com/datasheets/tone_signaling.html
although there are probably lots of other choices.
Likewise, you need a DTMF transmitter to send tones back to the sender.
Another option might be to find a phone that already does the conversion for you.
TTFN
RE: Receiving data via modem
Receiving DTMF is the real problem. I don't know of any modem command which will allow this.