ModbusPal - a Java MODBUS simulator / News: Recent posts

ModbusPal v1.6b is released

Important bug fix: previous version (v1.6a) would either crash, or at least the serial communication would not work start, even with RXTX properly install on the computer. The new version (v1.6b) fixes this major issue.

Posted by nnovic 2011-07-25

ModbusPal v1.6a is released

The new version of ModbusPal, v1.6a is available for download. The javadoc and the embedded HTML help are also available as separate zip archives. If you find anything wrong with this version (and I'm quite confident that there are still a few bugs), you are welcome to submit the issue in the MantisBT hosted app!

Posted by nnovic 2011-05-02

Goodbye v1.5, Hello v1.6

I didn't release ModbusPal 1.5 yet, because I couldn't find the time to finalize the tests and the documentation. Now I have to move on with the development, so ModbusPal 1.6 is on the way. It will introduce support of user-defined function codes (range 65-72 and 100-110 in the MODBUS specification), thanks to Python scripts.

Posted by nnovic 2011-04-07

Record/Replay feature added

The next version of ModbusPal will introduce the Record/Replay capability. Record a MODBUS session into a file, replay the session later and compare the results. Great for non-regression testing!

Posted by nnovic 2009-11-15

ModbusPal 1.5 on the way

ModbusPal is still under active development, despite the lack of recent updates. The next version will introduce modbus coils, increase productivity and introduce NullAutomation for your custom bindings.

Posted by nnovic 2009-10-19

ModbusPal 1.4 released

The new version of ModbusPal is here at last. The major modification is an improved integration of Python script in the projects, and a nice documentation explaining how to use the software!

Posted by nnovic 2009-05-27

WIP-1.4 soon to come

The next release of ModbusPal is still under development. It will offer a better integration of Python scripts, with the ability to create customized generators and customized bindings. Additionally, I have started writing a decent user manual.

Posted by nnovic 2009-04-22

ModbusPal: New release WIP-1.3

ModbusPal is a project to develop a PC-based Modbus simulator. The goal of ModbusPal is to reproduce a realistic environment, with many slaves and automated register values.

This version is able to use Jython in order to execute scripts. The release contains the executable Jar, the jevadoc and some script samples.

Posted by nnovic 2009-03-17

Wiki at

A wiki has been started. If contains very few information, but you can take a look at small Jython scripts written for ModbusPal.

Posted by nnovic 2009-03-11

ModbusPal script enabled!

ModbusPal is going to integrate Jython as a script engine in order to achieve complex modbus simulation. Jython is a Java interpreter for Python language.

Posted by nnovic 2009-02-27

Serial link implemented!

Modbuspal now uses the RxTx project in order to support serial communication. The RxTxComm api makes your Java application aware of the COM ports available on your laptop, and it runs on Windows and Linux systems.

Posted by nnovic 2009-02-24

Fully working alpha version

This new version is still a "work-in-progress" version, but the most important features are demonstrated and working:
- learn mode to create slaves and registers "on-the-fly"
- save and load projects in xml format
- automations to create dynamic values for the registers.

Posted by nnovic 2009-01-07

Development version

You can download the current development version of ModbusPal. It only works with TCP/IP and, supports "Read holding registers" and "Write multiple registers" requests, and there is no automation yet.

Posted by nnovic 2008-12-22