I want to write an API for ARM7 microcontoller to use unstructured supplementry service (AT+CUSD) to send to a TR800 gsm module. The basic ides is to send a Class-2 msg to the mobile (as in services provided by network providers). I can't seem to find the right method to do it.. I found the command syntax but there was nothing mentioned about the response and exactly when to use different parameters.
This has nothing to do with Keil tools or products!
If you have questions about a specific GSM Module's AT Command set, then you need to ask the module manufacturer about that!
You can always experiment manually with Hyperteminal...
And the USSD response will depend upon the specific service that you are using - so, again, you need to contact the service provider about that!