just a couple rs232 basics, 1) make absolutely sure transmitter and receiver are configured identically (baud rate, bit length, stop bits, and parity). 2) when you find out the rs232 commands enter them EXACTLY as written because everything has meaning. For instance a 0x in front of the command means it's a hexadecimal number and a trailing \r or 0x0D could indicate a carriage return which is necessary to complete the command. In general, once you are able to successfully complete one command the rest will be easy.