Module description: 1. The module adopts genuine quality relay, the maximum load of the normally open interface: AC 250V/10A, DC 30V/10A; 2. Using double optocoupler isolation, strong drive capability, stable performance; trigger current 5mA; 3. Each channel of the module can be triggered by jumper high or low level; 4. Fault-tolerant design, even if the control line is broken, the relay will not move; 5. Power indicator (green), 1 relay status indicators (red) 6. User-friendly interface design, all interfaces can be directly connected through the wiring terminals, very convenient Module interface: 1. DC+: Connect to the positive pole of the power supply (voltage is relay 5V) 2. DC-: Connect to the negative pole of the power supply 3 .IN: The relay can be controlled by high or low level Relay output: 1. NO: Relay normally open interface, before the relay is vacant, it will be shorted to COM after picking up 2. COM: Relay Common Interface 3. NC: Normally closed relay interface. Before the relay is closed, it is short-circuited with COM. High and low level trigger selection: 1. S1 is the high and low level trigger selection of relay 1; 2. When com is shorted to low, the corresponding relay is a low level trigger. When com is shorted to high, it is a high level trigger Note: 1.Due to the different monitor and light effect, the actual color of the item might be slightly different from the color which is showed on the pictures. 2.Please forgive 1 cm/0.39"-3 cm/1.18" measuring deviation due to manual measurement.