# TODO - PLC Client Web Project

## Objectives
- [x] Implement a Flask web server to display PLC data.
- [x] Replicate `plc_client.py` output in the web interface.
- [x] Improve S7 connection management (robust connection, clean exit).
- [x] Use external HTML/CSS/JS files.

## Tasks
### 1. Infrastructure & Setup
- [x] Create `todo.md` (Done)
- [x] Create folder structure:
    - `templates/` (for HTML)
    - `static/css/` (for CSS)
    - `static/js/` (for JS)
- [x] Initialize Flask app in `plc_client_web.py`.

### 2. Backend Logic (Migration from `plc_client.py`)
- [x] Analyze `plc_client.py` to identify core logic (polling, parsing, S7 connection).
- [x] Refactor S7 communication into a separate class or thread-safe module.
- [x] Implement robust connection handling (reconnect on failure, clean exit).
- [x] Implement data polling loop that updates a shared state (e.g., a global variable or a thread-safe object).

### 3. Frontend & Integration
- [x] Create `templates/index.html`.
- [x] Create `static/css/style.css`.
- [x] Create `static/js/script.js` to fetch data from the Flask server via AJAX/Fetch API.
- [x] Create Flask routes to serve the page and provide data as JSON.

### 4. Refinement
- [x] Match `plc_client.py` output exactly (initial phase).
- [x] Optimize polling frequency and UI updates.
- [x] Error handling and logging for the web version.

## Next Steps
- [ ] Transition from hardcoded DB names (DB900, DB901, etc.) to a configurable array of memory objects.
- [ ] Implement a persistent data logging system to save sessions to JSON/Database.
- [ ] Add advanced chart types (e.g. Histograms, multi-axis charts).