GSM sim900D with hyperterminal problem

[sogomogo]

I am trying to interface gsm sim900D with windows xp hyperterminal..problem is when i send AT command and enter..there is no reponse like "ok"..what should i do..is my gsm module faulty..when i turn pkey on it displays
RDY
+CFUN:1
+CPIN:ready
CALL READY

and when some one call on my sim it displays ringing and number and name of caller..it is not receiving messages...help me pls

 

[maros_d]

Hi,

It looks like the SIM900 works properly when you are receiveing answers from module.
Did you check HW wiring? Maybe the Tx pin from your PC is not connect on SIM900.. and also check hyperterminal serial properties: 9600, 8 bit, 1 stop bit, no parity, handshake off

And also SIM900 has UART voltage levels from 0V to 2.8V