ITEAD GSM SIM900A not able to connect on system serial of Arduino UNO

Hi everyone,

I am from Canada and I am able to call the module ITEAD GSM SIM900A from my cell phone when I apply 5V2A power but when I connect Tx and Rx Pins of this module with Arduino and try to run it using example code in Arduino software, I am not able to get any reply on serial terminal.

When I type AT in serial terminal I am supposed to get okay or system ready indicating that this module is compatible with Arduino but instead of that I am not able to get anything on serial terminal. I have tried changing location of Rx and Tx on pin 2 and 3 of Arduino but it is still not working.

Can anyone give me the idea what could be the problem I am not able to get reply on serial terminal.

Thank you.