i am using windows vista , xbee series 2, df robot xbee adapter and i have downloaded a terminal program: PUTTY, when i type (+++) to enter programming mode, i do not get an ok from the xbee and this happens even for x-ctu terminal and i have even tried it on coolterm. i do not know where the problem is. i do not know what to do
Baud rate correct? Try different Baud rates an check Baud rate with a scope.
Tx and Rx connections correct? Double check and use a scope to verify data coming from PC is going to the RX pin of the XBee.
Voltage levels and the correct level shifting? Use scope to check levels.
What PC port are you using? An RS232 Serial port? A USB port? with a USB to serial adapter?
Do you have the correct port selected for X-CTU or the Term prog?
df robot xbee adapter? Link to data sheet and schematic?