Feature: Using SMT optocoupler isolation, it has strong driving ability and stable performance; trigger current is 5mA; Modules can be triggered by setting high or low levels through wire jumper. Fault-tolerant design, even if the control line is broken, the relay will not move. The interface design is humanized. All interfaces can be directly connected through the terminal, which is very convenient. Equipped with 4 fixed screw holes, easy to install. Specification: Channel: 2 Product dimension: 50*41*18.5mm / 2*1.6*0.7in Power light: Green Relay light: Red Board color: Red Package list: 1 * Relay Module Note: Module interface: 1. DC+: Connect the positive pole of the power supply 2. DC-: Connect power supply negative pole 3. IN1:1 signal trigger terminal, can set high or low level control relay suction 4. IN2:2 signal trigger terminal, can set high or low level control relay suction Relay output: 1. NO1: 1 channel relay usually opens the interface. The relay is suspended before suction and short-connected with COM1 after suction. 2. COM1: 1 channel relay common Interface 3. NC1: 1 channel relay normally closed interface, short connection with COM1 before relay suction, suspension after suction 4. NO2: 2 channel relay often opens interface. The relay is suspended before suction, and is short-connected with COM2 after suction. 5. COM2: 2 channel relay common interface 6. NC2: 2 channel relay normally closed interface, short Connection with COM2 before relay suction, suspension after suction. High and low level trigger selector: 1. S1 is the trigger selection of high and low level 1 channel relay. 2. S2 is the trigger selection of high and low level 2 channel relay. 3.com and low short connection, the corresponding relay is low-level trigger, com and high short connection is high-level trigger.