This DLL assumes the device we are attaching to enumerates as a generic HID device. That is the data is passed as an array of bytes (usually 64). See the firmware in the Microchip Applications Library, "USB Device - HID - Custom Demos".
The DLL encapsulates the windows OS calls necessary to search though the list of connected devices and find the device with the specified Vendor and Product ID. Then once it's found it opens a pipeline to the device. It also automatically tries to reopen the device in case it has been disconnected and reconnected. This makes recovering from a disconnect/reconnect event seamless to the application.
The compilation setting must be /clr, /clr:pure or /clr:safe. This dll is a .NET assembly, so it can’t be used with a compilation setting that produces pure unmanaged code.