Run a Windows 7 x64 VM (Hyper-V or VirtualBox) and install the older SXSI version. Map your COM ports directly to the VM. This works even on a Windows 8 host.
These eliminate the need for Windows-specific sxsi.dll entirely. sxsi x64 windows 8 link
In Siemens automation ecosystems, (often part of SIMATIC S7-SCL or older WinCC components) acts as a System Extension Interface . Its responsibilities include: Run a Windows 7 x64 VM (Hyper-V or
Searching for "sxsi x64 windows 8" primarily yields results for the , a specialized piece of software used by professional videographers to enable high-speed data transfer from SxS storage media to a 64-bit Windows system. Sony SxS Memory Card Driver for Windows 8 (x64) sxsi x64 windows 8 link