Setting Up Your Xentry/DAS with a Serial Port Connection

For automotive diagnostic professionals and enthusiasts working with Mercedes-Benz vehicles, Xentry/DAS remains a crucial tool. While modern setups often utilize network connections, there are still scenarios and older systems where establishing a connection via a serial port is necessary. This guide provides a step-by-step approach to configuring your Xentry/DAS setup using a serial port, specifically focusing on utilizing a USB to serial adapter with an FTDI chipset for optimal compatibility and performance.

Essential Hardware and Software

Before diving into the configuration, ensure you have the necessary components:

• FTDI Chipset USB to Serial Adapter: This is paramount for reliable communication. FTDI chips are known for their stable performance and compatibility in automotive diagnostic applications. A recommended option is readily available online.

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• Virtual Machine Environment: Xentry/DAS often operates best within a virtual machine. Using software like VirtualBox allows you to create a controlled environment, especially if your diagnostic software is designed for older operating systems.
• Compatible Operating System Image: You’ll need a virtual disk image (.VHD format is recommended for VirtualBox, avoid .VDHX) containing a compatible operating system like Windows XP or similar, depending on your Xentry/DAS software version.

Virtual Machine Setup for Xentry/DAS

1. Create a Virtual Machine: In VirtualBox, create a new virtual machine and point it to your .VHD disk image. Ensure you configure the VM settings to match the OS on your disk image (e.g., RAM, processor).
2. Operating System Boot and Guest Additions: Start the virtual machine and boot into the OS. Crucially, install VirtualBox Guest Additions. This software suite enhances performance and integration between the host and guest operating systems, particularly for USB device handling. For Windows XP guests, ensure “Enable IO APIC” is checked in the VM’s System settings to prevent boot issues.

Configuring DAS and Addressing Copy Protection

Some Xentry/DAS installations, especially older versions, may incorporate copy protection mechanisms that trigger if hardware IDs change.

1. Disable Conflicting Services (Windows XP): In Windows XP within your VM, use msconfig to access the Startup tab. Disable any potentially conflicting services, such as Chinese language services or startup items related to copy protection (e.g., “ads,” “mote”). While some “Star” related items might be present, disabling them isn’t typically necessary for basic DAS functionality.
2. Replace DAS BIN Folder (If Necessary): If you encounter copy protection issues or missing DAS executables, you might need to replace the DAS “BIN” folder with one from a non-copy-protected source.

Setting Up the Serial Port for Xentry Communication

Now, configure the serial port to enable communication between Xentry/DAS in your VM and your diagnostic multiplexer.

1. Identify COM Port and Baud Rate in Star Utilities: Launch “Star Utilities” within your Xentry/DAS virtual machine. Navigate to “Self Tests” and then “DMI Self Diagnosis.” A window will appear displaying the COM port number and Baud rate that Xentry/DAS is configured to use. Note these values down.

2. Adjust Existing COM Port in Device Manager (Guest OS): Open Device Manager in your virtual machine and locate “COM ports.” Find the COM port identified in Star Utilities (it’s often COM2 by default). Go to its “Advanced Settings” and change its COM port number to the next available number (e.g., from COM2 to COM3). This step helps avoid conflicts when adding the USB serial adapter.

3. Connect USB Serial Adapter to Host and Guest: Plug your FTDI USB serial adapter into your host computer. It might not be necessary to install drivers on the host OS. In your virtual machine, go to the “Devices” menu, then “USB,” and select your “USB to Serial” device. This connects the adapter to your guest OS. The guest OS will detect the new hardware, and you should install the FTDI drivers within the virtual machine.

4. Configure FTDI COM Port Settings (Guest OS): After driver installation, find the newly added FTDI COM port in the Device Manager of your virtual machine. Open its properties, go to “Port Settings,” and configure the following:

   • Baud rate: Set it to the Baud rate you noted from Star Utilities (typically 115200).
   • COM Port Number: Change the COM port number to match the original COM port number from Star Utilities (often COM2).
   • Advanced Settings – Latency Timer: Crucially, in the “Advanced” tab of the FTDI COM port properties, reduce the “Latency Timer” to 1 ms. This setting is vital for reliable real-time communication in diagnostic applications.

   Alt text: Screenshot of the Advanced Settings for an FTDI USB to Serial Port in Windows Device Manager, highlighting the Latency Timer setting set to 1 ms.

Final Connection and Testing

1. Connect Multiplexer: Connect your serial cable to the FTDI USB serial adapter and then connect your Mercedes-Benz diagnostic multiplexer to the other end of the serial cable and the OBDII port of the vehicle.

2. Check Connection Status: Observe the status monitor within Xentry/DAS (usually in the taskbar). It should indicate a “Connected” status.

3. Verify with Star Utilities Self Test: Return to “Star Utilities” and run the “Self Tests” again. Ideally, all tests should pass. However, even if some tests fail, if the status monitor shows “Connected,” communication is likely established, and Xentry/DAS should function correctly.

   Alt text: Image depicting components of a Star Diagnosis system, including a laptop, diagnostic multiplexer, OBDII cable, and serial port connector.

Alternative USB Pass-through Method (If Direct Connection Fails)

If you encounter issues with directly connecting the USB adapter to the guest VM, you can try USB pass-through from the host operating system.

1. VirtualBox COM Port Configuration: In your VirtualBox machine settings, add a COM port. Configure the “Port Number” to match the COM port identified in Star Utilities. Select “Host Device” and in the “Path/Address” field, specify the host OS’s COM port number for your USB serial adapter (e.g., COM6).
2. Guest OS COM Port Adjustment (Potentially): Even with host pass-through, you might still need to adjust the COM port number within the guest OS’s Device Manager to ensure it matches the configuration expected by Xentry/DAS.

By following these steps, you should be able to successfully establish a serial port connection for your Xentry/DAS system, enabling you to perform comprehensive diagnostics on compatible Mercedes-Benz vehicles. Remember to always consult your specific Xentry/DAS software documentation for any version-specific instructions or recommendations.