n wrote:HI can I use GSM modem?
Yes you can, if the modem is accessible via PC's COM port number between COM 1 and COM 16.
In addition, the modem must implement the ETSI standard GSM 07.05 to provide the SMS functionality using AT commands (SMS Text Mode interface).
I recommend the GSM modem Siemens TC35i Terminal, if it is available in your country.