DIGSI 4.91 is a configuration and parameterization tool for Siemens protection devices, such as the Siprotec 5 and Siprotec 4 series. It's used to configure, monitor, and maintain these devices.
The official Siemens support forums confirm that the software is only compatible with . If you encounter this issue, your best course of action is to: siemens digsi 491 download verified