more separate modbus tools required with ModBuster!

Poll, Simulate, Parse, Test, Discover, Log, and Monitor… All in One Single Tool!

What is ModBuster?

ModBuster is a cross-platform desktop Modbus protocol toolkit available for Windows, Linux, and macOS systems.

What Protocol Variants does it support?

ModBuster works with all three variants specified in the Modicon Modbus Protocol Reference Guide.  This includes:  Serial RTU, Serial ASCII, and TCP.

Which network layers can be utilized?

ModBuster can transmit and receive data through a Serial Port, TCP, or UDP.

ModBuster is flexible when choosing a protocol variant to go with your selected network.  You can use any of the following configurations:

  • TCP Protocol over TCP
  • TCP Protocol over UDP
  • RTU Protocol over Serial
  • RTU Protocol over TCP
  • RTU Protocol over UDP
  • ASCII Protocol over Serial
  • ASCII Protocol over TCP
  • ASCII Protocol over UDP

Which Function Codes are supported?


  • 0x01 – Read Coils
  • 0x02 – Read Inputs
  • 0x03 – Read Holding Registers
  • 0x04 – Read Input Registers
  • 0x05 – Write Single Coil
  • 0x06 – Write Single Register
  • 0x15 – Write Multiple Coils
  • 0x16 – Write Multiple Registers

Not Supported, but planned for a future update:

  • 0x17 – Report Slave ID
  • 0x22 – Mask Write Register
  • 0x23 – Mask Read/Write Registers

What data formats are supported?


  • Boolean Coils/Inputs with configurable Named Aliases
  • 16-bit Signed, Unsigned, Binary-Coded Decimal, Bit-Within Reg (for alarm registers)
  • 32-bit Signed, Unsigned, Floating Point, Bit-Within Reg
  •  Byte-Order Swap & Word-Order Swap is supported for all register types.

How many different connections can I create?

ModBuster allows you to create as many connections as allowed by the performance of your machine’s cpu/memory.  You can also create Masters, Slaves, and Snoopers all within one running instance of ModBuster!

For example, you could have all of the following devices running simultaneously:

  • Modbus TCP Master, /
  • Modbus TCP Slave,
  • Modbus TCP Slave,
  • Modbus RTU over TCP Slave,
  • Modbus ASCII over UDP Slave,
  • Modbus RTU Master, COM4
  • Modbus RTU Slave, COM5
  • Modbus RTU Snooper, COM6
  • Modbus RTU Master, COM7
  • Modbus ASCII Master, COM8

For most regular machines, we recommend a maximum of 10 unique connections inside of a project for best performance.

What does ModBuster do that other tools don't?

ModBuster combines a lot of different feature sets that would normally be found in multiple different tools all into one single tool.

Firstly, ModBuster is Cross-Platform (Windows 7+, Linux, Mac) which allows all divisions of a business to use on their native device (Field Techs with Windows, Developers with Linux/Mac, etc).

ModBuster can also be a Modbus Master Driver, a Modbus Slave Simulator, and a Modbus Snooper simultaneously.

ModBuster has a unique ‘Table’ View for each connection.  This view differs slightly from a typical ‘grid’ view in that you can filter and search through all available points to organize your data by alias, function code, parser, current value, or any other filter category you can think of.  This makes working with very large data sets much easier.

ModBuster supports Binary-Coded Decimal and will let you read/write individual bits in a register without doing binary/decimal conversions in your head.

You can also alias coil/input values to more readable state (ie; 0=”Alarm”, 1=”Normal”)

ModBuster has solid logging capabilities; you can configure it to log all communications or only log special events like Modbus Errors or Timeouts.  Logging can automatically log to a file on your computer.

We also have four other “Special” features that are certainly not found altogether in one tool:

  • Device Discovery – Configurable scanning on an existing network which uses responses/timeouts to map which devices exist and what points are available. Useful for retrofits and investigating networks where the structure is not known and there is no documentation.
  • Serial Snooper – Allows you to “sniff” traffic on existing network and automatically create new modbus points in table view for each new successful master/slave communication packet pair.  Also a great feature for retrofits and for identifying serial communication issues on an existing network where you are unable to run your own master device.
  • Test Sequencer – Build, save, load, and execute modbus master command tests using a configurable rules engine.  Useful for commissioning known system builds or checking a point structure to ensure that your slave endpoints produce desired data.
  • Manual Packet Parser – Allows you to copy/paste custom hex into a text area to determine modbus packet structure.  Useful for checking data produced from other devices/tools.

We have a lot of big plans for expanding this tool to meet all of your modbus testing needs.  If you have a much-needed feature you would like to see added or tweaked, we would love to hear from you!  Please contact us.

Which serial port hardware do I need to work with ModBuster?

ModBuster should function with any type of Serial Port device that you can get working on your computer.

If you have free USB ports, you can purchase a USB to RS485 or USB to RS232 adapter to tie into your modbus network.  You can also use virtual COM ports, legacy DB9 serial ports, and more.

Why are there two different settings for "Slave Addressing Structure"?

The two different memory addressing settings allow you to simulate slave devices which manage registers in different ways.

For example, most modbus slaves implement a ’16-bit’ address space for all registers.  With this configuration, a master device would need to poll for quantity 2x registers in order to read and parse a 32-bit floating point.

However, other slave devices may implement an ‘Individual’ address space.  With this configuration, a master device would only need to poll for quantity 1x register, and the slave device would return all bytes necessary (4x, instead of 2x in the 16-bit example) required to parse the individual floating-point number.

The “Slave Addressing Structure” setting can be found in the ‘Advanced’ menu in both the Create/Edit Connection menus for any slave device.

What about other computing devices? Intel Edison? Raspberry PI?

ModBuster is not tested on any single-board computers, but may still work with limited functionality on some windows or linux SBCs.

We plan on expanding compatibility with these platforms in the future.

How does Licensing work?

The ModBuster licensing scheme is designed to allow you unlimited use of ModBuster on 1x machine.  After purchase of a license from this page, your email is used as your account identifier and the generated license is tied to your account.

Activating, Unactivating, and Transferring licenses are all easy processes that are built-in to the ModBuster application.

To activate, you must have ModBuster downloaded and installed and also have an active internet connection.  After activation is complete, you will not need an internet connection ever again on the activated machine (unless you need to unactivate/transfer a license key)

Currently, we do not support ‘Offline’ activation.

More information on Licensing can be found in our Help Documentation.

Is there a Demo Version?

You may download ModBuster from this page and use it free of charge without a license for as long as you wish.

This Demo version is limited to 1x Active Connection within the same project.  It also does not include saving/loading projects, Table View, the Test Sequencer, Manual Command, Device Search, or Manual Packet Parser.

Otherwise, there are no other limitations.

Does ModBuster support extended Modbus Slave ID Addressing?

Extended Modbus Slave ID Addressing changes the regular 1x byte used for the Slave ID (max slave id 255) to 2x bytes which extends the maximum number of slaves to 65535.

At the current time, ModBuster does not support extended modbus slave id addressing. We may develop and implement this feature in a later release.

For additional ModBuster information, please see our detailed Help Documentation.

ModBuster System Requirements

Requirements Windows Linux Mac
Operating System

Windows 7 Home, Pro, Enterprise, UltimateWindows 8/8.1 Standard, Pro, Enterprise

Windows 10 Home, Pro, Enterprise

x86 (32-bit) and x64 (64-bit) for all O.S.

Ubuntu 14.04+
Fedora 25+
Debian 8+
Linux Mint 18+
x86 (32-bit) and x64 (64-bit) for all O.S.
OSX 10.9 (Mavericks), OSX 10.10(Yosemite), OSX 10.11 (El Capitan)
macOS 10.12 (Sierra), macOS 10.13 (High Sierra)
x64 (64-bit) Only for all O.S.
CPU Dual-Core, 1.5GHz Dual-Core, 1.5GHz Dual-Core, 1.5GHz
RAM 2GB, 4GB Recommended 2GB, 4GB Recommended 2GB, 4GB Recommended
Storage 100MB 100MB 100MB

If your system does not meet these requirements, ModBuster may still function, but we can not guarantee its functionality.

Online payment and automatic license delivery will be available upon ModBuster’s release.