4.2.5 RS-485 (Modbus RTU)

Notes

• Register addresses can be given in decimal or hex (0x prefix).
• Always confirm register map, byte order, scaling, and offset from the sensor datasheet.
• Function code is fixed to 0x03 (Read Holding Registers) in this release.

Message format:

[0xAA][LEN_H][LEN_L][CMD][SUB][DATA...][CHK][0x55]

with XOR checksum.