1. Protection Functions: Three-stage overcurrent protection, three reclosing attempts, delayed acceleration, directional zero-sequence protection,  feeder automation - voltage-time type scheme, feeder automation - voltage-current type scheme. 
2. Signal Acquisition: Capable of collecting three-phase current, zero-sequence current, and zero-sequence voltage; 8 channels for input collection; 8 channels for analog signal collection, including 4 voltage signals and 4 current signals; distribution line loss measurement includes four-quadrant power and supports bidirectional measurement. 
3. Communication Functions: GPRS/3G and 4G universal communication, Ethernet communication, fiber optic communication. 
4. Fault Location and Recording Functions: Optimizes the existing ungrounded neutral system and enhances single-phase grounding fault line selection determination in low current grounding systems, improves fault waveform recording and uploading to the main station, supporting 64-channel storage. 

5. High-precision sampling of sensors and high-fidelity simulation signal waveform are the basis for the control unit, which, on top of traditional FTU functions, adds metering-level distribution line loss collection, optimizes low current grounding fault determination and location, and increases sampling frequency to make fault waveforms closer to real waveforms. 
6. Distribution Line Loss Collection: Through high-precision sampling of analog signals, it measures real-time energy data on the line, including forward and reverse active and reactive power and four-quadrant reactive power for bidirectional measurement and communication transmission. 
8. Low Current Grounding Fault Determination and Location: Utilizing the electronic transformer’s ability to preserve position characteristics of low current grounding fault points during high-frequency resonance, the control unit uses various algorithms to accurately locate the fault area. 
9. Fault Recording Function: Samples 128 points per cycle and fully records the waveforms of the first 4 cycles before the fault and the 8 cycles after the fault, as well as switch position and remote signal information, sending this to the main station for analysis of fault causes, with support for cyclic storage of 64 fault recordings.