On earlier 2G devices, the port is inside the case on the top part of the board
On later 2G devices and all 3G devices, the port is on the bottom of the case and accessible without removing any parts.
The pinout is a standard RS232 wiring of Transmit-Receive-Ground.
The most common connector uses a Molex PHR-3 connector on one end and a DB9 connector on the other end.
You can make your own cable using the instructions and images above, or you can request a cable from our support team.