The data contents are 0103H, the binary format is 0000 0001 0000 0011, write in
corresponding Y17~Y0, so Y0, Y1, Y10 are set ON.
Note: when writing the data contents, the low byte is before the high byte.
(6) Function code 10H: write multiple registers
Eg. Write 3 registers starting from address 0000H (D0).
RTU mode:
After executing, the value in D0, D1, D2 are 1, 2, 3.
Note: byte number = register number * 2.