MC7304 Seperate AT-Command Port

I’m working with the MC7304 on Windows Server 2008 R2 with the latest Drivers (Build v. 4277).

I can communicate with the Modem via the Modem command port (COM4). This is successful until a connection via the Modem is established.
Firmware is SWI9X15C_05.05.58.00 r27038 carmd-fwbuild1 2015/03/04.

Question: Is there a seperate AT-Command Port to communicate with the Modem while a the Modem is connected to the Internet?
The device Manager shows only two Serial Ports: 1) Sierra Wireless DM Port (COM5) and 2) Sierra Wireless NMEA Port (COM3).

Note: Previously i have worked with the MC8795V which shows a seperate AT-Command Port.

MC8795V is a DIP module, so you are able to see the AT port. But MC7304 is a QMI device which doesn’t have seperate AT command port.


Thanks for the answer.
But how do i e.g. send SMS or monitor the device status? Is there (or where do i get) a SDK for Windows?

you can find the Windows driver from the below path:



i have found the windows drivers previously… but i don’t find any sdk provided with the driver package?
What i need is a API/SDK for windows (for linux i have found this: … 03,-d-,10/)



The driver only presents a standard windows interface to the modem module.

The easiest way to send SMS from windows (now that you have the drivers installed) is probably to use the windows SMS api. As a start, have a look at the following:

A google search for “windows sms sdk” also brings up a bunch of third party tools and libraries.

Or … you could write an application that sends the appropriate AT commands to the modem over the virtual serial port.

ciao, Dave

What I need is a full replacement for the AT-Command Port, sending sms is not enough :unamused:

Meanwhile I have found the following Thread:

What do you mean with “virtual serial port”?

btw: i’m working with windows 2008 r2 x64…


It’s my experience that when these modules are enumerated by Windows, there are a number of devices registered - one of which is the AT command port which registers as a virtual serial port (eg COM something). This means that you can use a serial terminal program (Tera Term/Hyperterminal/PuTTY etc) to connect to the module and manually send AT commands. Or you can write a script or application which opens the serial port and sends AT commands.

The answer for obtaining the API is in the end of this thread:

So you’ll have to check with your local distributor to get it.

ciao, Dave

jep… this is true for the modem which i have used previously, but not for the MC7304.

I’m in contact with the distributor, but the first thing i received from them was a guide about at-commands… :frowning:

@Rex_alex: My distributor told me that he is in contact with SIERRA, but doesn’t get any useful response. Is there a contact person for distributors which is able to provide the sdk? My distributor feels a little lost…

THANKS for all your info davidc and Rex_alex!

I kind of have the same problems, discussed in another thread [url]]. There the answer was that there is no SDK for Windows for MC modules.

Seams to be a problem with SIERRA,
on this thread “lotam” said that there is an SDK:

Update on 17.08.2015:
Finally I have received a SDK which works from my Distributor.