Voltage and frequency relay, NA protection according to VDE AR-N 4105. Network and system protection in accordance with the VDE application rules VDE-AR-N 4105:2011-06 and 4105:2018-11, VDE-AR-N 4110:2018-11. Compliance with the BDEW guideline and DIN V VDE 0126-1-1, DIN V VDE V 0126-1-1/A1. Monitoring of over- and under-voltage and frequency, 10-minute average vector jump monitoring (ROCOF), monitoring of the frequency gradient df/dt. Single fault safe with monitoring of coupling switch island network monitoring (passive). Integrated 4-digit digital display for measurement values and programming. All values on the device are adjustable and readable. Pre-set basic programs according to the standards and guidelines, digital display for measurement values and programming of limit values. Hysteresis and switching times can be individually set for each alarm. MIN/MAX memory for measurement values, test button, and simulation function with measurement of switching times. Integrated alarm counter for 100 alarms, with relative timestamp and recording of total alarm time. Switching outputs: output relays 2 x 1 changeover, transistor outputs for reporting the switching cause. Operating status and alarm display with LEDs. Option for code protection for parameters and sealing for set values.