The answer is . Thousands of substations worldwide still run SIPROTEC 4 relays installed between 2005 and 2015. These relays are built to last 20+ years. Replacing a working SIPROTEC 4 relay with a new SIPROTEC 5 relay costs $5,000–$15,000 per unit plus engineering hours.
Yes, for relays with the RS485 port (e.g., 7SJ64 via the rear terminal). However, you must manually map the COM port number in Windows Device Manager to COM1-COM4, as DIGSI 4 often struggles with COM numbers above 10. siemens digsi 4.91 download
By [Author Name] – Power Systems Engineering Consultant The answer is
Once you obtain DIGSI 4.91, backup the installer and your license dongle in a fireproof safe. Finding this software again in 2028 will be even harder than it is today. Disclaimer: This article is for informational purposes. The author is not affiliated with Siemens AG. All trademarks are property of their respective owners. Always verify software licensing with your local Siemens representative. Replacing a working SIPROTEC 4 relay with a