Modbus RTU Command Baud Rate: 9600 8 NONE 1 Send hex Hexadecimal reception Steps: 1. Software setting the baud rate 2. Set the address (device address used to communicate) Set the address is: 01 00 06 40 00 00 01 5c 1b Set the address is: 02 00 06 40 00 00 02 1c 1a Read address 00 03 40 00 00 01 90 1b Read the software version 00 03 00 04 00 01 c4 1a // [month] broadcast read (only by one device, for all addresses practical, easy to test) 0,003,000,800,010,419 [years] // broadcast read (only by one device, for all addresses practical, easy to test) 00 03 00 10 00 01 84 1e [hour, minute] // broadcast read (only by one device, for all addresses practical, easy to test) Read the hardware version (PCB version) 0,003,002,000,018,411 // broadcast read (only by one device, for all addresses practical, easy to test) [1 Address] The 1st relay open 01 05 00 01 01 00 9d 9a Relay 1 closed 01 05 00 01 00 00 9c 0a The 2nd relay open 01 05 00 02 01 00 6d 9a 2 Relay Off 01 05 00 02 00 00 6c 0a The 3rd relay open 01 05 00 03 01 00 3c 5a 3 Relay Off 01 05 00 03 00 00 3d ca 4 relay open 01 05 00 04 01 00 8d 9b 4 Relay Off 01 05 00 04 00 00 8c 0b All off 01 05 00 ff 00 00 fd fa All light 01 05 00 ff ff ff fc 4a