Communication between devices and the Galaxy Software is done via a USB Cable manufactured by Spitronics. The reason for this is to reduce production cost and board space. These components are only used during tuning and you do not need the cable once the ECU/TCU are tuned. The electronics in the cable consist of the USB converter as well as isolation devices. This cable will protect the laptop during high voltage interference.
This cable requires drivers to be installed to operate. They can be downloaded from the Spitronics website under Downloads � USB Drivers. The baud rate to all products are 19200.
As development progressed over the years these product were upgraded as well. So keep in mind that cables between the products do differ. In some cases you may require an adapter to use the USB cable on different products. See the picture below.
TCU, EMU and Titan units were the fore runners. They used a RS232 to USB converter with a 9 Pin Male D-Sub connecter. With these units you had the option of a third party converter and breaking out pins. Note that this connecter is the same as the Mercury and Neptune one but the cable electronics is different. The electronics is not compatible with Venus, Mercury, Neptune or Pluto.
Venus used a USB to UART converter with a 9 Pin Female D-Sub connecter. This was to stop confusion and the different connectors was easy to identify the product it was used for. But the male pins on the ECU were susceptible for static spikes. During the era of the Venus the cable changed to the isolation cable due to laptops that �hang� with interference wiring. Some of the cables had the electronics in the wire covered with heat shrink and most have it in the D-Sub holder.
Mercury, Neptune and Venus2 were using the same electronics as the Venus cable except with the 9 Pin Male D-Sub connecter. We changed this unit back to the standard connector due to static electricity on the male pins that were exposed. Spitronics do solder the 9 Pin D-Sub connecters back to back to make USB cables between Venus, Mercury and Neptune compatible. See the picture above.
Pluto is the new generation cable. It will be standard to all the new products released. Here Spitronics have done away with the D-Sub connecter and go for a 6 Pin Molex connecter which is the same type as the harness connectors. The reason is it is plastic which eliminates the static connection with the human body and it clips in place preventing it from falling out during tuning. It is also more durable. With this cable the electronics is also in the wire covered with a plastic enclosure. Again this USB cables electronics is compatible with Venus, Mercury 2 and Neptune. You only require a converter cable harness to make it work.
Note that only the Spitronics USB cables are compatible with their products. They are not expensive cables.