Php – Sending SMS through USB interfaced GSM Modem in PHP

First of all, to send sms when modem is in pdu mode, you must send these commands: AT+CMGS=<length> <CR>, where length is (length of PDU binary string - 2) / 2. When '>' symbol appears you must send your pdu and ctrl+z character (char.ConvertFromUtf32(26)).

Here are some resources that may be useful: http://www.developershome.com/sms/ SMS Tutorial http://www.diafaan.com/sms-tutorials/gsm-modem-tutorial/online-sms-deliver-pdu-decoder/ another online pdu decoder (but your link is better in my opinion) http://www.fccps.cz/img.asp?attid=24590 AT commands guide (for wavecom, but there is no difference)

Last advice - use any telnet client to connect and test your modem and see how it responds

You could do:

Timer timer = new Timer(0, new ActionListener() {

   @Override
   public void actionPerformed(ActionEvent e) {
      updateRecords();
   }
});

timer.setDelay(30000); // delay for 30 seconds
timer.start();

Aside: Java naming conventions have methods starting with lowercase and underscores are generally not used so Update_Records becomes updateRecords.