Sorry i have no idea. Maybe my program code "sending a text message" can help you!
#include <SoftwareSerial.h>
#define SMSTEXT "Hello World" //const. string
SoftwareSerial GPRS(8, 9); //Define Rx und Tx for GPRS Shield communication
void setup() {
GPRS.begin(19200); // the GPRS baud rate
Serial.begin(19200); // the Serial port of Arduino baud rate.
delay(5000);
}
void loop() {
if (Serial.available())
switch(Serial.read())
{
case 's': //Press 's' to send an text message
SendSMS();
break;
}
delay (2000); // ... 2 seconds delay
}
//------------------------------------------------------------------------------------------------------------------
void SendSMS()
{
Serial.println ("Send SMS started!");
GPRS.print("AT+CMGF=1\r"); //Because we want to send the SMS in text mode
delay(100);
GPRS.println("AT + CMGS = \"+43xxxxxxxxxxxx\""); //This number will recieve the text message
delay(100);
GPRS.println(SMSTEXT); //SMSTEXT = constant
delay(100);
GPRS.println((char)26); //the ASCII code of the ctrl+z is 26
delay(100);
GPRS.println();
Serial.println ("Send SMS finished!");
}
If it not works, i hope that other forum users help you with your problem!