Edge computing unit for transformer and substation health monitoring
Smart Transformer ECU
4–20 mA, RS-485, Modbus TCP/IP, expansion connector and digital/analog I/O for temperature, humidity, smoke, water, access and breaker sensors
Processes alarms, profiles and status locally before sending to the Head-End via MQTT, IEC 60870-5-104 or DLMS/COSEM
Fault detection, trip indication and connection analysis, including HV-side line-fault monitoring and environmental alarms
Modular and configurable for existing substations, with an upgrade path to IEC 61850 and NCA cybersecurity requirements
The Smart Transformer ECU is a secure edge controller for transformer monitoring, diagnostics and connected utility operations. Built for transformer and substation environments, it is the gateway between the environmental, electrical and security sensors inside a substation: it collects, analyzes and securely transmits data to the utility’s Head-End system for real-time visualization and predictive maintenance.
Dual-core 32-bit LX7 microcontroller, up to 240 MHz
512 KB SRAM / 8 MB PSRAM (optional) / 16 MB Flash (typical)
FreeRTOS
Wi-Fi 4 (802.11 b/g/n) & Bluetooth 5 (LE); 1 × Ethernet; Modbus RTU & TCP/IP
1 × UART, 2 × GPIO, 4 × analog input, 2 × digital IN/OUT, Modbus RTU
Temperature, humidity, motion (PIR), light, button, 4–20 mA closed-loop transmitters
MQTT, WebSockets, Bluetooth, Modbus RTU and TCP/IP; edge to Head-End via MQTT, IEC 60870-5-104, DLMS/COSEM; IEC 61850 (MMS/GOOSE) ready via optional firmware module
Secure Boot and measured boot, flash encryption, AES/SHA/RSA hardware accelerator, TLS 1.3 with X.509 certificate authentication, secure MQTT broker integration, secure OTA updates, role-based access control, secure audit logging
220 V AC; 3.3 V DC (via USB)
−40 °C to +85 °C
IP65 enclosure, DIN-rail or wall mount
105 × 94 × 61 mm / 260 g
Designed in line with CE, RED, FCC and RoHS
Temperature & humidity sensor
RS-485 / Modbus RTU
Detect overheating, humidity ingress, ventilation failure
Smoke / gas sensor
RS-485 or 1-Wire
Fire and gas detection in transformer and RMU rooms
Water immersion sensor
Digital input
Detect floor flooding or oil leakage
Door magnetic sensor / smart lock
Digital input / RS-485
Detect unauthorized access; remote or local access control
CTs (LV): transformer load
Analog 4–20 mA / current loop
Measure LV current, load and phase unbalance
Smart meters (1 to n)
RS-485 / Modbus RTU or DLMS/COSEM
Per-feeder energy, phase and power factor
Smart main & sub breakers
RS-485 / Modbus RTU
Real-time breaker status, fault and trip data
Human presence / motion sensor
Digital input or I²C
Personnel detection for maintenance safety
PV / inverter power sensor (optional)
RS-485 / Modbus RTU
Monitor auxiliary power and solar backup lines
Live temperature, humidity, smoke, door status and breaker states
Per-feeder current, voltage and energy from CTs and smart meters
Smoke, water, intrusion, over-temperature and trip events with time stamp and severity
History of load, energy balance and environmental change for predictive maintenance
Geographic and tabular view of connected substations with live status
Role-based access and event audit logs in line with NCA security controls
ECU panel build on the common platform
Designed in line with: NCA ECC v1.0/v2.0, IEC 62443-4-1/4-2, SASO/IEC 61010-1 and the IEC 61000 series, IEC 60870-5-104, MQTT and DLMS/COSEM, IEC 61850 Ed.2 (future-ready), SEC SDMS Specification 34-TM/2022, CST GEN001/GEN003 and Saudi Vision 2030 objectives.
The Smart Transformer ECU shares its field-proven hardware platform with Rewellx Ultra and REECON RE1000. Electronics, firmware and features are configured for transformer and substation monitoring.
Engineered in Germany. Proven in the field. Built for Saudi Arabia.
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info@rewellxarabia.com 
+966 54 170 6399