Description: _x005f_x000D_ Relay communication: 485 communication in multi-unit network. Based on MBDBUS-RTU protocol, the default address is 1. Users can modify the address by themselves through instructions. _x005f_x000D_ Note: IN1 - IN4 is used to read switch status through 485, not through input control relay output. _x005f_x000D_ IN1-IN4 switch state needs to read the switch state every time the computer inquires, and can not send data to 485 actively. _x005f_x000D_ Note: IN1-IN4 does not connect 220V. _x005f_x000D_ _x005f_x000D_ Specification: _x005f_x000D_ Size: 76mm*67mm*17.5mm/2.99*2.63*0.68'' _x005f_x000D_ Weight: 79g _x005f_x000D_ _x005f_x000D_ Connection Mode: _x005f_x000D_ 1. IN1 - GND (default is high level, low level after switching on) computer sends instructions to read switch status. _x005f_x000D_ 2. IN2 - GND (default is high level, low level after switching on) computer sends instructions to read switch status. _x005f_x000D_ 3. IN3 - GND (default is high level, low level after switching on) computer sends instructions to read switch status. _x005f_x000D_ 4. IN4 - GND (default is high level, low level after switching on) computer sends instructions to read switch status. _x005f_x000D_ _x005f_x000D_ Note: _x005f_x000D_ Please allow 1-3mm differs due to manual measurement. _x005f_x000D_ Due to the different display and different light, the picture may not show the actual color of the item. Thanks for your understanding. _x005f_x000D_ _x005f_x000D_ Included: _x005f_x000D_ 1 X Modbus RTU 4 Way Relay Module