C# Desktop utility for communicating with MODBUS devices
This is a simple Windows application which allows the user to connect to a MODBUS device through a serial port. Right now the application only supports MODBUS RTU and MODBUS ASCII, but the underlying library supports MODBUS TCP/IP as well (but that hasn't been tested). See the list of known bugs for more information about the state of the app.
I was looking for an open-source MODBUS utility to use at work, and started by looking through this list on Modbus.org. Partway down was an entry called "Open-source Modbus Library in C#," and I followed it to an archive of the free-dotnet-modbus project, and that's what this application is based on. I created a new user interface, split the library (which was originally one huge C# file) into separate classes, and added/translated comments as I felt appropriate. I left the original author's release notes and readme untouched.
The first release is not yet available, so installation requires building from source. You need Visual Studio 2017 or later with Microsoft .NET Framework 4.7.2. After building, publish the solution to create an installer. After running the installer, the application will be available from the Windows Start menu.
The app will run without any hardware, but to do anything useful, you'll need a serial port and a device that uses the MODBUS RTU protocol.
- Select the serial port options.
- Click the "Open" radio button to open the port.
- Set the device address. There are text boxes for hex and decimal versions of the address, and as soon as you change one, the other will update.
- Go to the tab of the type of MODBUS register you'd like to read or write.
- Set the coil/input/register address. Like the device address, there are text boxes for hex and decimal input, and as soon as one is changed, the other will update.
- Click "Read" or "Write" to send the corresponding MODBUS message and listen for a response.
- When finished, click the "Closed" radio button to close the serial port. Closing the program will also close the port.
If something goes wrong (e.g. a timeout, corrupted message, etc.) a message will appear.
There are two licenses involved here. The original free-dotnet-modbus project appears to have used the GNU Lesser GPL license, so I've retained that for the library itself. The GUI project, which I wrote, I'm releasing with the MIT license.
So basically if you change anything in the Modbus folder, you need to open source your changes. If you change anything else, you can keep your changes as closed source if you choose.
If you've got something valuable, feel free to submit a pull request.