Modbus FAQ
Answers about Modbus frames, register addresses, byte order and browser serial debugging.
Topics
All questions22
Protocol basics
6Using the tools
5Troubleshooting
4Device integration
4Security and privacy
322 matching questions
What is Modbus?
Protocol basics
What are the four Modbus data areas?
Protocol basics
How do RTU, ASCII and TCP differ?
Protocol basics
What is the difference between function codes 03 and 04?
Protocol basics
What protocol address corresponds to register 40001?
Protocol basics
What does a Modbus RTU CRC check tell me?
Protocol basics
How do I generate a Modbus RTU request?
Using the tools
How do I parse a Modbus frame?
Using the tools
How do I use browser serial debugging?
Using the tools
Why is a decoded value wrong?
Using the tools
How are settings saved and results exported?
Using the tools
Why is my serial port unavailable?
Troubleshooting
Why does CRC verification fail?
Troubleshooting
Why does the device not respond?
Troubleshooting
Why is communication intermittent?
Troubleshooting
How should I poll several serial devices?
Device integration
How do I choose a floating-point byte order?
Device integration
How can I reduce polling time?
Device integration
Can I work with vendor-specific function codes?
Device integration
Does the website upload my input data?
Security and privacy
What should I check before using a tool with production equipment?
Security and privacy
How should Modbus devices be protected from network access?
Security and privacy
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