How to use a modem driver

[gerald.monin]

Hi,

I'm developping an application that should transfer data via a modem. This is already working using the AT commands, but this is depending on the modem's manufacter. All modems are not configured all the same and some clients have problems with their own modem.

Is there a way to use the Windows driver installed with the modem ?
I'm looking for an example or explanation how to do that.

Many thanks in advance,
Gerry

[smercurio_fc]

I don't think that's going to help you in this case. The driver just provides a protocol for Windows on how to send data, not a protocol for the actual data. Is the modem connected via the serial port? If so, the AT commands are just sent over the serial port to the modem, and these commands are understood by the modem to configure certain things or perform specific actions. Anything else the modem should just send over the communication link. Hayes had established a set of "standard" AT commands that all Hayes-compatible modems should understand. Of course, manufacturers were still free to make up their own commands.

It sounds like your app needs a set of config files for support of various modems that you can come across. You can set up the config files so that you can add them after the app has been distributed in order to support new modems.

[rolfk]

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@Etrelec wrote:
Hi,

I'm developping an application that should transfer data via a modem. This is already working using the AT commands, but this is depending on the modem's manufacter. All modems are not configured all the same and some clients have problems with their own modem.

Is there a way to use the Windows driver installed with the modem ?
I'm looking for an example or explanation how to do that.

Many thanks in advance,
Gerry

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Yes doing your own modem driver generally can be a pain. Depending on what you want to do you can sometiems get away with a configuration possibility for the initialization string that you send as first command to the modem after opening the connection link to it. This string will have to be entered by the user based on his modem or if you want to get very fancy you can try to detect the modem type and pick a default string based on that.

Using the Windows provided modem driver is not trivial if you want to have control over the data link that is build up through that modem. One other approach that has worked in the past for me, was to completely let Windows handle everything and using the modem connection for a dialup setup. This dialup adapter itself was installed in the Windows networking software to provide a TCP/IP link. Now in LabVIEW you can simply use the TCP/IP nodes to communicate. This however of course requires that the remote side is a TCP/IP endpoint too.

Rolf Kalbermatter