The board offers individual control of two electromagnetic relays, with load circuits of 10A at 250V. The control pins are isolated by optocouplers, ensuring high safety and guaranteeing that no spikes will appear in the control electronics. The board is powered by supplying 5V to DC+ and GND to DC-. The control pin levels are 5V tolerant. The control pins are driven by active high/low voltage, set by jumpers S1 and S2. Position H sets active high voltage, and position L sets active low voltage. The relay interfaces have normally open circuits. All three relay outputs are brought out to the output terminal – normally closed, common, and normally open, marked as NC, COM and NO.