Feature:1. The relay has a long service life, and can be connected continuously for 100,000 times2. The module has high‑performance control chip, which can meet various work needs3. With a variety of functions to ensure the stability and safety of work4. Professional design and reasonable structure, easy and convenient to install5. Suitable for the computer uses serial port debugging software to send serial commands to control the on and off of 2 channel relaysHow to Use:COM1: Common terminal;NC1: Normally closed, the relay is short‑connected with COM1 before it is closed, and it is suspended after it is closed;NO1: Normally open terminal, the relay is suspended before the pull‑in, and short‑circuited with COM1 after the pull‑in.COM2: public end;NC2: Normally closed terminal, the relay is short‑connected with COM2 before it is closed, and it is suspended after it is closed;NO2: Normally open end, the relay is suspended before being closed, and shorted to COM2 after being closed.COM2: CommonNC2: Normally closed, the relay is short‑connected with COM2 before the pull‑in, and it is suspended after it is pulled‑inNO2: Normally open end, the relay is suspended before the pull‑in, and short‑circuited&