Modbus Tools

Overview

ModbusTools are cross-platform (Windows, Linux) Modbus simulator tools (client and server) with GUI to work with standard Modbus Protocol. Modbus Tools are a free, open-source tools with a simple user interface written in C++/Qt. It implements TCP, RTU and ASCII versions of Modbus Protocol.

Software implements such Modbus functions as:

• 1 (0x01) - READ_COILS
• 2 (0x02) - READ_DISCRETE_INPUTS
• 3 (0x03) - READ_HOLDING_REGISTERS
• 4 (0x04) - READ_INPUT_REGISTERS
• 5 (0x05) - WRITE_SINGLE_COIL
• 6 (0x06) - WRITE_SINGLE_REGISTER
• 7 (0x07) - READ_EXCEPTION_STATUS
• 15 (0x0F) - WRITE_MULTIPLE_COILS
• 16 (0x10) - WRITE_MULTIPLE_REGISTERS
• 22 (0x16) - MASK_WRITE_REGISTER (since v0.3)
• 23 (0x17) - READ_WRITE_MULTIPLE_REGISTERS (since v0.3)

ModbusTools work with Qt Framework version 5 (5.8 or later). It based on ModbusLib cross platform library project:

https://github.com/serhmarch/ModbusLib

Release

All compiled binaries are located in the latest release:

https://github.com/serhmarch/ModbusTools/releases

About Modbus Client

The client implements access to a remote Modbus device. However, the client can work not only with one device, but with several devices that can be connected to a single network, which is especially useful when working with RTU and ASCII protocols, when access to all Modbus servers is realized through a single serial port. However, it can also be useful when using the TCP version of the protocol, for example, if you use the TCP->RTU bridge.

All work is done within a single project. The main entities in the project are Port, Device and DataViewItem. Port contains network settings for both TCP/IP and serial ports. Device contains settings for a single device (such as Modbus Unit Address, etc.).
The DataViewItem contains a single data unit to be read from the remote device and has many formats to represent the current data.

Send Message window

The client has the ability to process one separate Modbus function with full configuration of the parameters of this function, view/edit read/write data with the format specified, view Modbus packets of this function:

This window can be opened using menu Tools->Send Message. It works in parallel with regular Modbus application messages and can be seen in LogView as regular Modbus message as well.

Scanner window (since v0.3)

Scanner tool window is intended to scan Modbus network to determine which device with current settings are present in the network. This window can be opened using menu Tools->Scanner

Scanner scans Modbus network in range [UnitStart:UnitEnd] with tries attempts count. The request can be customized using Scanner Request-dialog, which is called using ... button in Request field.

There is a list of found devices in central widget. Found devices can be add to the current project: button To Project add selected devices, All To Project - all devices will be added to the project.

About Modbus Server

The server implements Modbus server device and works like Modbus simulator. However, the server can not only simulate single device, but can simulate several devices that can be connected to a single network, which is especially useful when working with RTU and ASCII protocols, when access to all Modbus servers is realized through a single serial port. However, it can also be useful to simulate Modbus network using the TCP version of the protocol, for example, if you use the TCP->RTU bridge, Modbus server can replace this bridge with remote devices for testing purposes.

All work is performing within a single project. The main entities in the project are Port, Device, DataViewItem and Action. Port contains network settings for both TCP/IP and serial ports. Device contains settings for a single device (such as Modbus Unit Address, memory size etc).
The DataViewItem contains a single data unit to be read/write from the device and has many formats to represent the current data. Action provides simulation capabilities (automatic change of device memory values).

Server Actions window

The server has the ability to simulate/change data (actions, automaticaly change values) with predefined action types (Actions tab near LogView, menu View->Actions window and menu Actions):

• Increment - changing value by adding or subtracting (if incrementValue < 0) incrementValue
• Sine - sine function with parameters of period, shift, amplitude
• Random - randomly changing values with specified range
• Copy - move data from one memory part to another (with same or different memory types)