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 convenientModule interface:1. DCand: Connect to the positive pole of the power supply (voltage is relay 5V)2. DC-: Connect to the negative pole of the power supply3 .IN: The relay can be controlled by high or low levelRelay output:1. NO: Relay normally open interface, before the relay is vacant, it will be shorted to COM after picking up2. COM: Relay Common Interface3. 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 triggerNote: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.