FU-ES EchoSense Instruction Manual
  • ⚠Safety Instructions
  • This instruction manual version is v1.0
    • Manual Update Log
  • Measurement principle and usage scenario
    • Firmware Update Date and Version Feature Description
  • Warranty
  • Exterior, Specs, Model
  • Installation and Setup
    • Mechanism Installation
    • Mechanical and Electrical iInstallation
    • Parameter setup
      • Z02 Automatic Pipe Size Detection Guide
  • Human Machine Interface
    • Introduction of human machine interface
    • Hybrid Page Setup and Usage Interface Guide
    • Monitoring Screen
    • Simulation Mode
    • Data interpretation on monitoring screens
    • Password input page
    • Setup screen
  • Communication
    • OCT output
    • Analog current output (0-20mA, 4-20mA)
    • RS485 and Modbus RTU Setting
    • Modbus RTU Protocol
      • Read-only memory read instruction(04) and memory lists
      • Read-Write Memory List
      • Read/Write Memory Read Command (03)
      • Read-write memory single Register write instruction(06)
      • Read/Write Memory Dual-Register Write Command (30)
      • Read/Write Memory Four-Register Write Command (31)
      • Single Bit Data Read/Write Commands (01/05) (Commonly Used in HMIs)
  • Parameters Table
    • Z Category Options and Descriptions
    • A Category Options and Descriptions
      • A02 Preset Pipe Specification Table for Different Models
      • A03 ~ A07 Data Range Explanation Based on Model Specifications
    • B Category Options and Descriptions
    • K Category Options and Descriptions
    • C Category Options and Descriptions
    • D Category Options and Descriptions
    • E Category Options and Descriptions
    • F Category Options and Descriptions
    • H Category Options and Descriptions
    • Pagasfsae 1
    • Page 1
  • Alarm and description of system conditions
  • Troubleshootings and Abnormalities
    • Iout 4-20/0-20mA debug process
    • OCT Alarm Debug Process
    • OCT Pulse Debug Process
    • RS485 Debug Process
  • Certification
  • FU-ES Product Page
  • LORRIC English Website
  • LORRIC Integration and Application Center
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  • Communications format
  • Terminology
  • Definition and function of memory
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  1. Communication

Modbus RTU Protocol

PreviousRS485 and Modbus RTU SettingNextRead-only memory read instruction(04) and memory lists

Last updated 5 months ago

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 is divided into two categories, read-only and read-write.

Read-only type is mainly for flow meter status related memory, such as instantaneous flow rate. This is also the most commonly used memory. Detail information in following page:

Read-write memory is mainly to set-up parameters such as pipe diameter, and to reset variables, such as set zero on the cumulative flow. Read-write memory is only readable by using instruction 03. You can only change one parameter at a time with the write operation. If the length of the target register is 1, please use instruction 06. If the length is 2 registers, please use instruction 30. Please see read-write memory detail page below:

Read-write memory instruction detail information as below:

Read-only memory read instruction(04) and memory lists.
Read-write memory list
Read-write memory read instruction(03)
Read-write memory single Register write instruction(06)
Read-write memory double Register write instruction(30)