Accurate solar resource data starts with stable sensor positioning and reliable acquisition in the field. SEMS-2000 combines a compact 2-axis Sun tracker with an MTD3K-based datalogger control unit, giving unattended sites one integrated system for automatic monitoring of direct, diffuse and global solar irradiance.
The tracker continuously aligns mounted sensors with the Sun using an astronomical elevation-azimuth algorithm. This supports DNI, DHI and GHI measurement with pyrheliometers, pyranometers and an optional shadow disk kit. Pointing accuracy is ±0.1° on both axes and can be improved to better than ±0.01° with the optional active Sun sensor.
Remote operation is built into the system architecture. The datalogger manages Sun position calculation, power supply, pointing status, data acquisition and communications, with options for GSM/GPRS/3G/Wi-Fi/WiMax supervision. Low consumption, 12 V battery operation and solar panel charging support long-term use in remote photovoltaic, solar thermal, research and meteorological installations.
The tracker follows altitude and azimuth using an astronomical algorithm that calculates Sun position from location, date and time.
The structure supports brackets for two pyrheliometers and one pyranometer, with optional shadow disk, Sun sensor and spectral sensor configurations.
The MTD3K-based datalogger samples, stores, processes and transmits sensor data while supplying power and control to the tracker.
The system supports RS485 half-duplex communication and remote access options including GSM/GPRS/3G/Wi-Fi/WiMax.
Operating logic includes night standby, reduced holding torque, ultra-low-power mode and critical power handling for autonomous operation.
A 16-bit tracker status word provides information for communication, tracking, reset, position, StallGuard and calibration alarms.
