https://github.com/SquareWaveSystems/opcilloscope
Browse and monitor OPC UA servers from your terminal. Lightweight, cross-platform, keyboard and mouse friendly.
https://github.com/SquareWaveSystems/opcilloscope
dotnet iiot industrial-automation opc opc-client opc-ua opcua opcua-client terminal tui
Last synced: 4 months ago
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Browse and monitor OPC UA servers from your terminal. Lightweight, cross-platform, keyboard and mouse friendly.
- Host: GitHub
- URL: https://github.com/SquareWaveSystems/opcilloscope
- Owner: SquareWaveSystems
- License: mit
- Created: 2026-01-05T00:57:01.000Z (5 months ago)
- Default Branch: main
- Last Pushed: 2026-02-14T09:27:29.000Z (4 months ago)
- Last Synced: 2026-02-14T16:59:00.010Z (4 months ago)
- Topics: dotnet, iiot, industrial-automation, opc, opc-client, opc-ua, opcua, opcua-client, terminal, tui
- Language: C#
- Homepage:
- Size: 4.28 MB
- Stars: 97
- Watchers: 4
- Forks: 7
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Roadmap: docs/ROADMAP.md
Awesome Lists containing this project
- awesome-tuis - opcilloscope - time oscilloscope view for industrial automation (Table of Contents)
README
# opcilloscope
**A lightweight, cross-platform OPC UA client for the terminal.**
Browse, monitor, and subscribe to industrial automation data right from your terminal. Keyboard-driven with mouse support. No bloated GUI, no complex setup, no license fees.
[](https://dotnet.microsoft.com/download/dotnet/10.0)
[](LICENSE)
[](https://github.com/gui-cs/Terminal.Gui)
## Why opcilloscope?
| Traditional OPC Clients | opcilloscope |
|------------------------|--------------|
| Heavy desktop apps | Single portable binary |
| Minutes to install | `curl \| bash` and you're running |
| Resource-hungry GUIs | ~40 MB RAM |
| Windows-only | Windows, Linux, macOS (x64 & ARM) |
| Click-heavy workflows | Keyboard-driven, mouse support |
**Use cases:** commissioning (verify PLC tags), troubleshooting (live values during fault diagnosis), integration testing (validate OPC UA server configs), recording (export to CSV for reports).
## Features
- **Browse** — Lazily explore the OPC UA address space. Expand only what you need.
- **Monitor** — Subscribe to variables with `Enter`. Real-time updates via OPC UA pub/sub, not polling.
- **Inspect** — Full node attributes: Description, DataType, AccessLevel, ValueRank.
- **Scope** — Real-time multi-signal oscilloscope (up to 5 signals, 30 s sliding window).
- **Trend Plot** — Single-signal trend view with auto-scaling.
- **Record** — Export monitored values to CSV. Zero data loss — every server-pushed sample is captured.
- **Configure** — Save/load connection and subscription configs (`.cfg` JSON files).
- **Themes** — Dark (default) and light.
Scope view — a soothing sine wave
How signal sampling works
opcilloscope does **not** poll your OPC UA server. The server *pushes* value updates using OPC UA's built-in publish/subscribe mechanism.
```
OPC UA Server
│ pushes values every 250ms (configurable 100ms–10s)
▼
opcilloscope receives value change events
├─→ Scope View — stores every sample (up to 2,000 per signal)
├─→ Trend Plot — stores last 200 samples in a ring buffer
└─→ CSV Recording — writes every sample to disk (zero data loss)
```
Data capture and screen rendering are decoupled:
| What | Rate | Details |
|------|------|---------|
| Server → Client updates | ~4 Hz (250 ms) | Default publishing + sampling interval, adjustable in connect dialog |
| Scope / Trend Plot redraw | 10 FPS (100 ms) | Renders whatever samples arrived since last frame |
| CSV recording | Every update | Captures 100% of server-pushed values, flushes every 10 records |
The scope view holds a sliding **30-second window** (zoomable 5 s – 300 s). Display resolution is limited by terminal width — each character cell is one data point.
## Keyboard Shortcuts
| Key | Action |
|-----|--------|
| `Tab` | Cycle between panes |
| `Enter` | Subscribe to selected node |
| `Delete` | Unsubscribe from selected variable |
| `Space` | Toggle selection / pause scope |
| `S` | Open scope with selected variables |
| `T` | Show trend plot |
| `W` | Write value to node |
| `+` / `-` | Zoom in / out (scope) |
| `Ctrl+O` / `Ctrl+S` | Open / save configuration |
| `Ctrl+R` | Toggle CSV recording |
| `?` | Help |
## Install
**Linux / macOS:**
```bash
curl -fsSL https://raw.githubusercontent.com/SquareWaveSystems/opcilloscope/main/install.sh | bash
```
**Windows (PowerShell):**
```powershell
irm https://raw.githubusercontent.com/SquareWaveSystems/opcilloscope/main/install.ps1 | iex
```
Or grab a binary from [GitHub Releases](https://github.com/SquareWaveSystems/opcilloscope/releases).
Then run:
```bash
opcilloscope
```
Linux dependency: ICU libraries
opcilloscope requires ICU libraries at runtime for globalization support.
```bash
# Debian 13 / Ubuntu 24.04+
sudo apt install libicu72 # or: sudo apt install libicu-dev
# Fedora / RHEL
sudo dnf install libicu
```
Uninstall
**Linux / macOS:**
```bash
curl -fsSL https://raw.githubusercontent.com/SquareWaveSystems/opcilloscope/main/uninstall.sh | bash
```
Or manually:
```bash
rm ~/.local/bin/opcilloscope
rm -rf ~/.config/opcilloscope/ # optional: remove config files
rm -rf ~/.local/share/opcilloscope/ # optional: remove OPC UA certificates
```
**Windows (PowerShell):**
```powershell
irm https://raw.githubusercontent.com/SquareWaveSystems/opcilloscope/main/uninstall.ps1 | iex
```
Or manually:
```powershell
Remove-Item "$env:LOCALAPPDATA\Opcilloscope" -Recurse -Force # binary
Remove-Item "$env:LOCALAPPDATA\opcilloscope" -Recurse -Force # OPC UA certificates
Remove-Item "$env:APPDATA\opcilloscope" -Recurse -Force # config files
```
If you installed to a custom directory (`OPCILLOSCOPE_INSTALL_DIR`), replace the paths above with your custom install location.
## Quickstart (Developer)
Requires [.NET 10 SDK](https://dotnet.microsoft.com/download/dotnet/10.0).
```bash
git clone https://github.com/SquareWaveSystems/opcilloscope.git
cd opcilloscope
dotnet build
dotnet run
```
Run tests:
```bash
dotnet test
```
## OPC UA Test Servers
**Built-in test server** (Counter, SineWave, RandomValue, writable nodes):
```bash
dotnet run --project Tests/Opcilloscope.TestServer
# Starts at opc.tcp://localhost:4840
```
**Public servers** (no setup required):
| Server | Endpoint URL |
|--------|--------------|
| OPC UA Server | `opc.tcp://opcuaserver.com:48010` |
| Eclipse Milo | `opc.tcp://milo.digitalpetri.com:62541/milo` |
**Docker** ([Microsoft OPC PLC](https://github.com/Azure-Samples/iot-edge-opc-plc)):
```bash
docker run -p 50000:50000 mcr.microsoft.com/iotedge/opc-plc:latest \
--autoaccept --unsecuretransport
# Connect to opc.tcp://localhost:50000
```
## Contributing
Contributions welcome! Please submit an issue or a pull request.
## License
MIT — see [LICENSE](LICENSE).
Built by Square Wave Systems
Inspired by lazygit