Reverse Engineering of Laser Cutter Controller RDLxxx and RDCAM Software

PC Connection

The controller is connected to the PC via USB 1.1 in full speed mode. The PC sees a FT245R chip from Future Technology Devices Internaltion Ltd. (FTDI), which is a common USB to serial port converter chip. This Chip is recognized by Windows (tested on XP and newer) and Linux (tested on 2.6.18 and newer) as a serial port.

The RDCAM software for Windows does not use the standard serial port functions, but relies on the FTDI driver D2XX instead. However, it seems that the software just uses standard serial port communication with the following settings:

All data bytes transmitted and received on the serial connection are lightly scrambled.