Solution:

The majority of the time if you have a male port (pins) you have a DTE. If you have a female port (holes) you have a DCE. You can use a voltmeter to check your RS-232 port to see if it is pinned out as DTE or DCE. Connect the black probe of the Multi-meter to ground. (this is pin 5 on a DB9 and pin 7 on a DB25) Touch the red probe of the multi-meter transmit and then to receive. (DB9 =pin 2 is receive and pin 3 is transmit. DB25= Pin 2 is transmit Pin 3 is receive) If there is voltage on receive you have a DCE If there voltage on transmit you have a DTE. 9 pin2 = RX3 = TX5 = GND 25 pin 2 = TX3 = RX7 = GND See White Pager below for detailed information: http://www.bb-elec.com/Learning-Center/All-White-Papers/White-Papers-Category1/FAQ-RS-232-Connections-That-Work.aspx