Modbus RTU Protocol
Communications format
bit order: lsb first
byte order: big endian
Data bits:8
Parity: None
Stop bits: 1
Floating point number follows IEEE754-1985. The float32 below stands for 32bits Single precision floating point number.
Terminology
Register: Length of 2 Byte or 16bit which is unit length of memory in Modbus RTU.
Byte: 8 bit length
Definition and function of memory
Modbus Memory Access
Modbus-accessible memory is divided into two main categories: read-only and read/write.
The read-only memory primarily contains data related to the flow meter’s operational status, such as instantaneous flow rate. This category is the most commonly accessed memory area. Read-only memory can only be accessed using Function Code 04 (Read Input Registers).
Relevant register mappings and details can be found on the following page:
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