The "100 251" designation is typically associated with the hardware unit itself, while the software (often called or TRUCKS ) provides the interface for technicians to perform tasks like:

Accessing technical data and unlocking secure gateways for modern vehicles. Where to Download the Software

Clearing fault codes (DTCs) and performing full system scans.

Official software and updates should always be sourced from authorized platforms to ensure security and vehicle compatibility.

For a successful setup of your DS150E unit with its corresponding software, follow these general preparation steps: How to Install Delphi 10.4 on Windows 10/11 FREE

Configuring replacement parts and key coding.

If your hardware is for dissolved gas analysis (DGA) rather than automotive, software like Delphi Diagnose v5.1 is hosted by Doble Engineering . Installation & Setup Guide