EthernetIP Simulator

A virtual PLC simulator that implements the EthernetIP/CIP protocol, allowing Studio 5000, RSLogix, and other SCADA systems to connect for testing and development -- no physical hardware required.

Built for automation engineers, integrators, and developers who need a quick way to test EthernetIP communications without a real PLC.

Built & maintained by Industrial Monitor Direct -- USA-based manufacturer of rugged industrial panel PCs, touchscreens, and embedded computers for automation.

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Quick Start

Option A -- Run from source:

git clone https://github.com/imdtouch/EthernetIP-Simulator.git
cd EthernetIP-Simulator
python main.py

Dependencies install automatically on first run. If that fails, run pip install -r requirements.txt manually.

Option B -- Run the pre-built executable (Windows):

Download EthernetIP_Simulator.exe from this repository and run it directly. No Python installation needed.

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Features

• Virtual PLC Server -- Simulates an EthernetIP device on port 44818 that accepts connections from SCADA software
• Tag Management -- Create, edit, and delete tags with inline editing, undo/redo, and context menus
• All Standard Data Types -- BOOL, SINT, INT, DINT, LINT, USINT, UINT, UDINT, REAL, LREAL, STRING
• Arrays -- Single and multi-dimensional array support
• User Defined Types (UDTs) -- Define complex data structures with custom members
• Modern Dark UI -- Built with PySide6 (Qt6) with a dark industrial theme
• Persistent Storage -- Tags persist between sessions via SQLite
• Auto-Install -- Dependencies are installed automatically on first run

Requirements

• Python 3.8+ (not needed if using the .exe)
• Windows 10/11 (recommended) or Linux
• Internet connection for initial dependency installation

How to Use

1. Create Tags

1. Click "Add Tag" in the Tag Management panel
2. Set the tag name, data type, and optional initial value
3. Click "Create Tag"

Tag names must start with a letter or underscore and contain only alphanumeric characters and underscores (standard PLC naming rules).

2. Start the Server

1. Click "Start Server" in the Server Control panel
2. The status indicator turns green when the server is running
3. Note the IP address and port (default: 44818)

3. Connect from Studio 5000 / RSLogix

1. Open your Studio 5000 project
2. In I/O Configuration, add a new Ethernet Module
3. Set the IP Address to the one shown in the simulator's Server Control panel
4. Set Port to 44818 and Slot to 0
5. Download to the PLC and browse Controller Tags -- your simulator tags will appear
6. You can now read and write tag values between Studio 5000 and the simulator

Editing Tags

• Double-click a value cell to edit inline
• BOOL tags toggle on double-click
• Ctrl+Z / Ctrl+Y to undo/redo value changes
• Right-click for context menu (Copy Name, Copy Value, Delete)

Keyboard Shortcuts

Shortcut	Action
Ctrl+Q	Exit application
F12	Capture screenshot & submit feedback
Ctrl+Z	Undo tag value edit
Ctrl+Y	Redo tag value edit

Supported Data Types

Type	Description	Range / Size
BOOL	Boolean	True / False
SINT	Short Integer (8-bit)	-128 to 127
INT	Integer (16-bit)	-32,768 to 32,767
DINT	Double Integer (32-bit)	-2,147,483,648 to 2,147,483,647
LINT	Long Integer (64-bit)	64-bit signed
USINT	Unsigned Short Integer	0 to 255
UINT	Unsigned Integer	0 to 65,535
UDINT	Unsigned Double Integer	0 to 4,294,967,295
REAL	32-bit Float	IEEE 754 single precision
LREAL	64-bit Float	IEEE 754 double precision
STRING	Character String	Up to 82 characters

Project Structure

EthernetIP-Simulator/
├── main.py                       # Entry point (auto-installs dependencies)
├── requirements.txt              # Python dependencies
├── EthernetIP_Simulator.exe      # Pre-built Windows executable
│
├── src/
│   ├── models/                   # Data models (Tag, UDT, DataType)
│   ├── database/                 # SQLite persistence (thread-safe)
│   ├── services/                 # Business logic with caching
│   ├── server/                   # EthernetIP/CIP server (cpppo)
│   ├── ui/                       # PySide6 interface & dialogs
│   └── feedback/                 # Screenshot annotation system
│
├── build/                        # PyInstaller build scripts
└── data/                         # Runtime data (created automatically)

Architecture

The codebase follows a layered architecture:

Layer	Responsibility
Models	Data structures (Tag, UDT, DataType enums)
Database	SQLite persistence with thread-safe, lock-protected cursors
Services	Business logic with O(1) cached tag lookups
Server	EthernetIP/CIP communication via cpppo (thread-safe)
UI	PySide6 dark-themed interface

Troubleshooting

Application won't start

• Verify Python 3.8+ is installed: python --version
• Try manual dependency install: pip install -r requirements.txt

Server won't start

• Check if port 44818 is already in use by another application
• Verify your firewall allows traffic on port 44818
• On Windows, see WINDOWS_SOCKET_GUIDE.md for port management tips

Studio 5000 can't connect

• Confirm the server status shows "Running" (green indicator)
• Make sure the IP address in Studio 5000 matches what the simulator displays
• If testing on the same machine, try 127.0.0.1
• Check that both machines are on the same network

Tags not appearing in Studio 5000

• Create tags before starting the server
• After adding new tags, restart the server
• In Studio 5000, re-download the configuration

Need Industrial Hardware?

This simulator is built by Industrial Monitor Direct, a USA-based manufacturer of industrial computing solutions. When you're ready to move from simulation to production, we offer:

• Rugged Panel PCs & HMI Touchscreens -- IP65/IP66 rated for factory floor environments
• Fanless Embedded Box PCs -- designed for 24/7 industrial operation
• Industrial Tablets -- mobile SCADA access on the plant floor
• Custom OEM Solutions -- wide-temp operation (-20°C to 60°C), UL/CE/FCC certified

All products come with a 3-year warranty and US-based technical support.

Website	industrialmonitordirect.com
Email	Support@IndustrialMonitorDirect.com
Phone	1 (207) 800-1637

Contributing

Contributions are welcome! To contribute:

1. Fork this repository
2. Create a feature branch (git checkout -b feature/my-feature)
3. Commit your changes (git commit -m "Add my feature")
4. Push to the branch (git push origin feature/my-feature)
5. Open a Pull Request

For bugs or feature requests, please open an issue.

License

This project is licensed under the MIT License.

Version History

v2.0.0 (Current)

• Complete UI rewrite from CustomTkinter to PySide6 (Qt6)
• Dark industrial theme with sortable, resizable columns
• Right-click context menus and inline tag value editing
• Undo/redo support (Ctrl+Z / Ctrl+Y)
• F12 screenshot annotation and feedback system
• Thread-safe database and server operations
• O(1) tag lookup via secondary cache index
• Removed 6 unused dependencies for a leaner install

v1.0.0

• Initial release with EthernetIP server, tag management, array support, and CustomTkinter UI