Settings Reference
Open Settings from the gear icon in the left sidebar. Settings are organised into three tabs.
Connections tab
Section titled “Connections tab”PLC connection
Section titled “PLC connection”A toggle at the top of this section lets you choose the connection method: S7 WebServer (default) or OPC UA. See WebServer Setup and OPC UA Setup for how to enable each on your PLC — OPC UA currently covers fewer features (no diagnostic buffer, alarms, or runtime info yet).
S7 WebServer fields:
| Setting | Description |
|---|---|
| IP Address | IP address of the PLC WebServer (e.g. 192.168.0.1). Do not include http:// or https://. |
| Username | WebServer user account name. Created in TIA Portal → Security Settings → Users and roles. |
| Password | WebServer password. Never saved to disk — required each session. |
OPC UA fields:
| Setting | Description |
|---|---|
| Endpoint URL | The PLC’s OPC UA endpoint, e.g. opc.tcp://192.168.0.1:4840. |
| Username | OPC UA user account name. Optional — leave blank to connect anonymously if your PLC allows it. May be configured separately from the WebServer login. |
| Password | OPC UA password. Never saved to disk — required each session, same as the WebServer method. |
Both methods:
| Setting | Description |
|---|---|
| Connect / Disconnect | Establishes or closes the PLC session. |
| Status dot | Green = connected, red = disconnected or error. |
TIA Portal MCP
Section titled “TIA Portal MCP”| Setting | Description |
|---|---|
| Connect / Disconnect | Starts the bundled MCP server and attaches to the running TIA Portal instance. TIA Portal V21 must be open with a project loaded. |
| Status dot | Green = server running and connected to TIA Portal. |
In development builds only, an additional field lets you specify a custom path to the MCP server executable.
Ladder Migration MCP
Section titled “Ladder Migration MCP”| Setting | Description |
|---|---|
| Connect / Disconnect | Starts the bundled Ladder Migration MCP server. |
| Status dot | Green = server running and ready. |
AI Agent tab
Section titled “AI Agent tab”Model Provider
Section titled “Model Provider”A toggle lets you choose between Anthropic and OpenAI-compatible — the latter covers Ollama, OpenAI, OpenRouter, or any other endpoint that speaks the OpenAI API. See Setup & Models for a full walkthrough of each provider.
Anthropic fields:
| Setting | Description |
|---|---|
| API Key | Your personal Anthropic API key. Stored encrypted on your local machine using the Windows DPAPI. Never transmitted to S7 PLC Buddy’s servers. |
| Model | The Claude model to use (Opus 5, Sonnet 5, Haiku 4.5, or a custom model ID). |
OpenAI-compatible fields:
| Setting | Description |
|---|---|
| Base URL | The API endpoint, e.g. http://localhost:11434/v1 for Ollama. Quick-fill buttons are provided for Ollama, OpenAI, and OpenRouter. |
| API Key | Optional — leave blank for a local Ollama instance, which needs no authentication. Stored encrypted, sent only to the Base URL above. |
| Max Output Tokens | Optional override for the model’s response length cap. Defaults to 4096 if left blank. |
| Model | Free-text model ID exactly as your provider expects it, e.g. llama3.1 or openai/gpt-4o-mini. |
A note appears in the app when a local endpoint is configured: tool-calling reliability varies more with local and smaller models than with Anthropic or a hosted provider.
Workspace Folder
Section titled “Workspace Folder”| Setting | Description |
|---|---|
| Workspace Folder | The local folder the AI Agent can read from and write to. Click Browse to choose a folder. Default: ~/Documents/S7 PLC Buddy. |
System tab
Section titled “System tab”License
Section titled “License”| Element | Description |
|---|---|
| License status | Shows your current tier: Free Trial (N days remaining), Pro, or Expired. |
| Upgrade / Manage | Opens the S7 PLC Buddy website to purchase or manage your Pro license. |
| Activate License | Opens the license dialog to enter a Pro license key. |
Diagnostics
Section titled “Diagnostics”| Element | Description |
|---|---|
| Log file path | Path to the application log file: %APPDATA%\S7 PLC Buddy\logs\main.log |
| Show in Explorer | Opens the log folder in Windows Explorer — useful when sending logs to support. |
| Element | Description |
|---|---|
| Version | Current installed version (e.g. 0.2.1). |
| Machine ID | A unique fingerprint of this machine, used by the licensing system. Click the copy icon to copy it to the clipboard. Useful if you need to contact support about a license issue. |
Where settings are stored
Section titled “Where settings are stored”All settings are stored in an SQLite database at:
%APPDATA%\S7 PLC Buddy\plc-buddy.dbSensitive values (Anthropic API key, OpenAI-compatible API key, license key) are encrypted using the Windows Data Protection API before being written to the database. The PLC/OPC UA password is never written — it is held in memory only for the duration of the session.
Conversation history and messages are also stored in this database.