How do I communicate with a modem or with a com port?

Hi,

Does anyone happen to know how you can communicate with a com-port in VB? At this moment I know how to check for available com-ports on your PC and how to send a string of data to this port.

But how do you receive output from that port?
When I send ATI1 to my modem on COM4, then how do I receive it's reply?

I am not using the MSCOMM control, so I guess I'd have to use API calls, but which ones?

Does anyone know how to communicate with a com-port- and the device on the port or know where I can find some examples/tutorials?

Thanks,

vbDan

I prefer to use MSComm OCX control, because when the InputBufferSize <> 0 then the control will fire the comEvReceive event, so you will know the Modem have reply something to you.

May be you can try to send a "ATZ" command to Modem, and you should received a "OK" from your modem. (It depand on you modem setting, whether return result in Text format or interger format).

for more information you can always refer to the following web site http://www.modemhelp.org/sets.html or email me

CreateFile can open handles to files, pipes, comm ports and devices. It's really rather clever ;-)


td.

Thank you for your replies,

I have tried using CreateFile to open the COM port; which went ok, then I used WriteFile to send a command, which seemed to work ok and then I tried using ReadFile to see what the modem had to say, which didn't seem to work.

I now found a control which is quite similar to the MSCOMM control, so I am amble to connect to the port and send and receive commands to and from the modem. It all seems to work using this control.

However; I have no idea how to start playing a wave file as soon as the modem picks up the phone? I want to be able to let the person who called hear a greeting message based on his/her Caller ID.

I would really appreciate it if someone can explain to me how to play a wave file through my modem.

And TumblingDown? Could you perhaps show an example of how to use CreateFile, WriteFile and ReadFile to communicate with your modem?

vbDan