Modbus Debugging Assistant WeChat Mini Program -8-in-1 Protocol Tool Full Evaluation

1, Introduction: Pain points and breakthroughs in Modbus debugging

Support exporting collected data as CSV files for further analysis in ExcelModbus Still the absolute main protocol for on-site device communication. FromPLCTo the frequency converter, From thermostat to electric meter, From sensors to relay modules, Modbus Everywhere.

But traditional Modbus There are several core pain points in debugging methods: (1) A laptop must be brought to the site; (2) Multiple software installations are required——Modbus Poll, Modbus Slave, Serial port assistant, Message analyzer……; (3) Data interoperability between different software, Low debugging efficiency; (4) High learning threshold, Novices are at a loss when faced with a bunch of parameters.

WeChat Mini Program modbusDebugging Assistant " Born to solve these problems. It will 8Funds Modbus Tools Integrated into WeChat, Covering from message generation, Protocol analysis, Device scanning, The complete link from station simulation to online learning. This article will focus on functionality, Message format, Three dimensions of practical examples, Conduct in-depth evaluations of these 8 tools.

Two, Tool panorama: 8Each tool has its own responsibilities

Three, Modbus RTU Deep analysis of tools

3.1 Request generator

RTU The tool provides a completeDual mode operation interface——Switch between using the "Request Command Generator" and "Response Parser". The generator supports switching between concise mode and advanced mode: The concise mode only requires four parameters: station address, function code, starting address, and quantity, Expand the full function code parameters in advanced mode, Data type selection, Byte order configuration.

Supported function codes: 01 (Reading coil) , 02 (Read discrete inputs) , 03 (Read and hold registers) , 04 (Read input register) , 05 (Write a single coil) , 06 (Write a single register) , 0F (Write multiple coils) , 10 (Write multiple registers) ——Covered Modbus All commonly used function codes of the standard protocol.

Eight types of data: UINT16, INT16, UINT32, INT32, FLOAT32, UINT64, INT64, FLOAT64. For32Position and64Position type, The tool automatically processes dual register/four register combinations, Support switching between large and small byte order.

3.2 Response parser

Paste the original hexadecimal response message, Tool auto completion: (1) Identification of slave station address; (2) Function code recognition and Chinese mapping; (3) The data domain is parsed according to the configured data type and byte order; (4) CRC16Verification comparison——Display green correctly✓, Error display in red✗And mark the correct value; (5) Automatic recognition of abnormal codes——When the highest digit of the function code is 1, Extract exception codes and display Chinese explanations (01=Illegal function code, 02=Illegal address, 03=Illegal data values, 04=Equipment malfunction) .

3.3 CRC16 Verify transparency

CRC16 Calculate parameters: Polynomials 0xA001 (Reversed CRC-16-IBM 0x8005) , Initial value 0xFFFF, XOR result 0x0000, Low byte first. The tool automatically adds in generation mode CRC At the end of the message, Mark the verification results in parsing mode——Completely eliminated manual inspection CRC The pain of the table.

3.4 Practical examples

Example1: Read the temperature value: Slave station address01, Function code03, Starting address0000, Read 2 registers → send out 01 03 00 00 00 02 C4 0B. Response 01 03 04 00 FA 02 8A XX XX Resolve as:: The first register=00FA (250) , the second=028A (650) , Usually represents temperature25.0°C, Humidity65.0%.

Example2: Write a single coil: Slave station address01, Function code05, Coil0000, ON → send out 01 05 00 00 FF 00 8C 3A.

Example3: Write multiple registers: Slave station address01, Function code10, Starting address0000, Write 2 registers, The values are:100And200 → send out 01 10 00 00 00 02 04 00 64 00 C8 XX XX.

Four, Modbus TCP Deep analysis of tools

4.1 MBAP Message header structure

TCP The core value of tools lies inMBAP (Modbus Application Protocol) Message headerAutomated management. MBAPThe header contains 7 bytes: Transaction identifier (2Byte, Request/Response Pairing Tag) , Protocol Identifier (2Byte, Fixed0000) , Length (2Byte, Subsequent byte count) , Unit identifier (1Byte, amount toRTUThe address of the slave station) .

In traditional debugging, Engineers need to manually concatenate these 7 bytes before reassembling themPDU, Low efficiency and prone to errors. TCPThe tool fully automates this process——Enter the address of the slave station (Unit identifier) After the function code parameters, The tool automatically generates a complete setTCPFrame.

4.2 TCP ↔ RTU Bidirectional conversion

TCP → RTU: Remove MBAP Head (The first 7 bytes) , Add CRC16 Verification (The last 2 bytes) .
RTU → TCP: Remove CRC16 Verification (The last 2 bytes) , Add MBAP Head (The first 7 bytes) .

This function is on the serial server (Like USR-N510) Especially practical in debugging——Can be done throughTCPTool generates messages, Convert toRTUThen send it through the serial port, Verify whether the transparent transmission of the serial server is correct.

4.3 TCP Example message

Read and hold registers: Request 00 01 00 00 00 06 01 03 00 00 00 0A (AffairsID=0001, agreementID=0000, Length=0006, UnitID=01, Function code03, start0000, Read10One) .
Response 00 01 00 00 00 17 01 03 14 00 64 00 C8 ... (Length=0017=23Byte, Data length=14=20Byte) .

Note Under the mode: TCPNo, VerificationThe integrity of data transmission is determined byCRCVerification, The integrity of data transmission is determined byTCPProtocol stack guarantee. This is the most confusing point for beginners.

Five, Modbus ASCII Tools—Undervalued debugging tools

Modbus ASCII Use 2 bytes per byteASCIICharacters (0-9, A-F) express, Add a starting character (:) And the ending symbol (CRLF) , Make the messageCompletely readable. Although efficiency is limitedRTUHalf of it, But it cannot be replaced in the following scenarios: (1) 7Old equipment with numerical data; (2) Pure text debugging——Can manually input and read messages; (3) ThroughTelnetOr the scenario of terminal simulator communication.

Frame format: :地址(2字符) 功能码(2字符) 数据(N×2字符) LRC(2字符) CRLF
LRCVerification: Add all bytes together (Excluding: andCRLF) , Take the lower 8 bits of the binary complement code.

Example: send out :010300000001F6rn (Read address01From the station, Function code03, start0000, Read one, LRC=F6) .

Six, Modbus Poll Pro — Industrial grade polling monitoring

Modbus Poll Pro Simulated the desktop end Modbus Poll The core experience of software:

• Multi device polling: Simultaneously monitor multiple slave devices, Each device is independently configured with an address, Function code, Register range, Data type
• Real time trend curve: Select any register, Automatically draw real-time waveform diagrams, Easy to observe the fluctuation trend of sensor data
• Register table view: ToExcelThe style table displays the addresses of all registers, name, Original value, Analysis value, Timestamp
• Data export: Support exporting collected data asCSVDocuments, Easy to accessExcelFurther analysis will be conducted

Suitable for the scene: Equipment aging test, Long term data collection, Batch equipment inspection.

Seven, ModScan32 Pro — Batch address scanning

ModScan32 Pro Solved common confusion when launching new devices——"What is the register address mapping for this device? "It can batch scan registers within a specified address range, Automatically detect which addresses are responding, What value was returned.

Core parameters: Starting address, Scanning quantity, Function code, Data type, Timeout period. After scanning is completed, display a list of all responsive addresses and their values, Support one click copying or exporting.

Eight, ModSim32 + Modbus Slave — From the station's twin heroes

8.1 ModSim32: Equipment level simulation

ModSim32 The simulation isReal slave devicesOverall behavior——Create an instance, Configure register area, Set the initial value and range of the register, Define response behavior. Multiple instances can be started simultaneously, Simulate different devices separately.

8.2 Modbus Slave: Register level simulation

Modbus Slave Provides finer register level control: (1) Four zone full simulation——Coil (Coils) , Discrete input (Discrete Inputs) , Input register (Input Registers) , Maintain registers (Holding Registers) ; (2) Manually set any register value; (3) Abnormal code simulation——After selecting the slave device, Can simulate the return of exception codes 01/02/03/04; (4) Template saving——One click saving and loading of commonly used register configurations.

Practical usage: developmentModbusWhen using the main station program, Use Modbus Slave Simulate real devices, Verify the reading of the main station, write in, Exception handling logic——No hardware required.

Nine, Modbus Learning classroom — From zero to mastery

This is a toolOnly oriented towards training and learningThe module, Contains five subsystems:

• Introduction to Illustration: Using the metaphor of classroom roll call to explain the master-slave relationship, Use envelope opening animation to display message structure, 6Each chapter progresses step by step
• Frame assembly practice: Interactive assemblyRTU/TCP/ASCIIMessage, Each click on a parameter (Address/function code/data/CRC) , Synchronized refresh of frame structure diagram
• Communication simulator: Animation display main station→The entire process of communication from the station (Request→handle→Response) , Supports four scenarios: read/write/exception/timeout
• quiz: Multiple choice questions+fill in the blank questions+true/false questions, Coverage function code/address/verification/exception code, A detailed explanation is provided for incorrect answers
• Quick reference manual: Function code lookup table+data type comparison+register address range+CRCOnline calculator+troubleshooting checklist+baud rate time calculator

Ten, Usage method

1. Open WeChat, Click on the top search button
2. Input modbusDebugging Assistant "
3. Enter the mini program, All 8 modelsModbusThe tool can be used without logging in

No need to install any software, No need to bring a laptop. Your phone is yoursModbusDebugging workstation.

Eleven, Summary

modbusDebugging Assistant "will Modbus Debugging has been moved from the desktop to the mobile phone, 8The tool covers everything from message analysis to device simulation, The complete chain from polling monitoring to online learning. Whether you are an on-site engineer, PLCProgrammers or automation majors, This set of tools can help youModbusDoubling debugging efficiency.

Recommended reading: Why? So popular Modbus What is? And? | What is the relationship Modbus? | Modbus What is the difference between a master station and a slave station RS485 All tools described in this article are free to use in WeChat mini programs? | Modbus Open WeChat?

🎯 Click on the top search button

Input → Debugging Assistant " → Enter the mini program modbusNo need to download → No registration or login required.
No need to downloadAPP, No registration or login required, No need for a computer——70+ Industrial control debugging tool, Just take out your phone and you can use it.

Whether you are on the construction site, During business trips, Still studying at home, modbusDebugging assistants are all industrial automation debugging workstations that you carry with you.