Chakkarapani, you are not saying much about your hardware. I hope you have used a max3232 to connect the Fbus to the PC otherwise you have burned the Rx line. (Fbus is 3.3 Volts)
http://www.datasheetcatalog.org/data...ts/max3232.pdf
Most of the AT command (not all) works also with Fbus.
Alberto




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