Hi nikator,
I was worked on this command set on hyperterminal, i'm familiar with the software i don't know that much of hardware.
please observe this,
AT\r\n
Response:OK
AT + CMGF = 1\r\n
Response:OK
AT+CMGS = "SIM NUM"\r
Resopne:>write message <CTRL+Z>
AT+CMGS:MSG NUMBER
This is the process i was followed for my project, it's worked fine for me.my advice is first check the voltages of the Tx & Rx pins of the modem and check that other pins also,observe the commands once again.
Thanks & Regards,
Chandu.Kurapati.