Protocol:LC default communication rate: 9600Bps;LC Communication Protocol:Data (1)----starting identifier (default: 0xA0)Data (2)----Switch address code (default: 0x01, identified as the first switch)Data (3)----Operation data (0x00 is "OFF", 0x01 is "ON")Data (4)----check codeExample:TURN ON: A0 01 01 A2TURN OFF: A0 01 00 A1HOW TO USE:1, plug the USB relay into the computer, install the CH340 to serial port chip driver;2, open STC-ISP, SSCOM32 and other serial debugging software, select the rate of 9600, send "A0 01 01 A2" turn on relay in hexadecimal (hex) form; send "A0 01" in decimal (hex) 00 " TURN OFF relay;USB intelligent control switch.Onboard high-performance -controller chip.Board CH340 USB controller chip.Onboard Power LED and relay status LED.Onboard 5V, 10A / 250VAC, 10A / 30VDC relay, relay life long continuous pull 100,000 .Relay modules with overcurrent protection and freewheeling diode protection.colour:blueMaterial:PCBsize:49.6*16mmPackage Contents:1 x USB relay moduleOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.