CAS Modbus TCP Parser

Have you ever needed to analyze a series Modbus TCP message?
Are you having unexplainable problems with your Modbus devices?The CAS Modbus TCP Parser can analyze a series Modbus TCP message, displaying any error message, what data is being read/written and what device the messages are coming from, and more…Features:

  • Debug error messages in Modbus TCP messages
  • Reads Ethereal(r) capture logs
  • Simple to use
  • Free. (No email required)


Executable (166k)
Please Read the copyright and disclaimer before downloading this tool.



This is an example a common Modbus TCP message being analyzed.

Frame Analysis
The frame has no errors.

Poll Analysis
Device Address  = 11      = 0x0b
Function        = 23      = 0x17 = Read or Write 4x Registers
Read Point Addr = 40005
Read Qty        = 6
Write Point Addr= 40016
Write Qty       = 3
	Write Data: Point Address  =40016   Value =255  =0x00ff
	Write Data: Point Address  =40017   Value =255  =0x00ff
	Write Data: Point Address  =40018   Value =255  =0x00ff

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