CAS Modbus Tool Kit User Guide: RTU/TCP Message Resolution and Scanner

Introduction to Chipkin Automation Systems (CAS) Modbus Tool

Chipkin Automation Systems We are a Canadian company specializing in building automation and industrial protocol gateways, Official website www.chipkin.com. Apart from commercialization BACnet And Modbus Outside of gateway products, Chipkin It also provides a series of free options Modbus Debugging and testing tools, include:

• CAS Modbus RTU Parser: Online Modbus RTU Message parsing tool
• CAS Modbus TCP Parser: Online Modbus TCP Message parsing tool
• CAS Modbus Scanner: Downloadable Modbus Equipment data scanning tool

These tools are very lightweight, You can use it by opening the browser (Parser) , Or run it with just one click after downloading (Scanner) . For occasional analysis needs Modbus For the message engineer, Compared to installation Wireshark + Configuring the environment is much faster.

CAS Modbus RTU Parser

Access address: store.chipkin.com/products/tools#modbus-rtu-parser

This is a web tool, No installation required. You just need to string it Modbus RTU Paste the hexadecimal bytes of the message into the input box, The tool will automatically parse it out:

• Slave station address (Slave Address)
• Function code and its meaning (Like 03 = Read Holding Registers)
• Starting address and number of registers (Request frame)
• Number of data bytes and specific data values (Response frame)
• CRC Verification value (And verify if it is correct)

Usage examples

Assuming you receive a string of hexadecimal data in the serial assistant:

01 03 00 00 00 0A C5 CD

Paste to CAS Modbus RTU Parser Afterwards, The automatic parsing result is::

• Slave Address: 1
• Function Code: 3 (Read Holding Registers)
• Starting Address: 0
• Quantity: 10 A register
• CRC: 0xCDC5 (Verification passed ✓)

Similarly, Verifying response frames is also convenient:

01 03 14 00 64 00 C8 01 2C 01 90 01 F4 02 58 02 BC 03 20 03 84 03 E8 DE B1

Analysis results: From the station 1, Function code 3, Byte count 20 (10 A register) , In sequence: 100, 200, 300, 400... Each value accounts for 2 Byte.

CAS Modbus TCP Parser

Access address: store.chipkin.com/products/tools#modbus-tcp-parser

And with RTU Parser similar, But it added parsing Modbus TCP MBAP The function of the head. Enter hexadecimal bytes to obtain: Transaction ID, Protocol ID, Length, Unit ID And complete PDU Analysis.

Example message:

00 01 00 00 00 06 01 03 00 00 00 0A

Analysis:

• Transaction ID: 1
• Protocol ID: 0 (Modbus)
• Length: 6 Byte (Subsequent content)
• Unit ID: 1 (Slave station address)
• Function Code: 3 (Read and hold registers)
• Starting Address: 0
• Quantity: 10

CAS Modbus Scanner

CAS Modbus Scanner It is a downloadable desktop tool, Used for scanning and reading Modbus All register data of the device. The download link is also available store.chipkin.com/products/tools/cas-modbus-scanner.

Functional characteristics

• support Modbus TCP And Modbus RTU (Through serial port)
• Can scan all four types of data: Coil (Coils) , Discrete input (Discrete Inputs) , Maintain registers (Holding Registers) , Input register (Input Registers)
• Support from address 0 Start the complete address space scan
• Display real-time data values, Supports both hexadecimal and decimal display formats
• Export scan results to CSV Documents

Typical usage scenarios

When you receive an unknown Modbus Equipment (There is no complete register mapping table) , When it is necessary to quickly understand which readable registers it has, CAS Modbus Scanner It is the fastest solution. Just need:

1. Set connection parameters (IP Address and port, Or serial port parameters)
2. Select the address range to scan (Like 0-100)
3. Click Start Scan
4. Check the returned data values and exception codes, Determine which addresses are valid

use CAS Tools are used Modbus Reverse analysis of equipment

Without an equipment manual, Through CAS Scanner Performing reverse register analysis is a practical skill. Basic ideas:

1. First, conduct a small-scale scan (Like 0-50) , Confirm which addresses return valid data
2. Changing conditions near known physical quantities (Such as heating temperature sensors, Rotary encoder) , Observe which registers' values change
3. Infer the register type based on the change pattern (16Bit integer/32Bit floating point/32Bit integer)
4. Record the register address and its corresponding physical meaning, Build a register mapping table

Chipkin Other industrial control tools

Besides Modbus Outside of tools, Chipkin The following free tools are also provided:

• BACnet Explorer: Browse and test BACnet Devices on the network
• CAS BACnet Explorer: BACnet Protocol device discovery and data browsing
• Modbus Explorer: Enhanced version Modbus Device browser

These tools can all be obtained from store.chipkin.com/products/tools Free download and use.

Summary

CAS Modbus The biggest advantage of the toolkit is that it is "ready to use""——Parser it is a web-based tool that does not require installation, Scanner it can be installed and used immediately after downloading. when you encounter a string of incomprehensible messages during on-site debugging Modbus or when you receive an unknown device without a manual, this free tool can help you quickly complete message parsing and address space scanning Modbus saving a lot of time browsing protocol documents and writing test scripts, This free tool can help you quickly complete message parsing and address space scanning, Save a lot of time browsing protocol documents and writing test scripts.