Glossary¶

This glossary defines key terms used in the Homematic(IP) Local integration for Home Assistant. Understanding these terms helps in troubleshooting and communication.

Home Assistant Ecosystem¶

Integration¶

An integration is a component that connects Home Assistant to external services, devices, or platforms. Homematic(IP) Local is an integration that connects Home Assistant to Homematic devices via a CCU backend. Integrations are configured in Settings → Devices & Services.

App (formerly Add-on)¶

An app is a self-contained application that runs alongside Home Assistant OS or Supervised installations. Apps are managed through Settings → Apps. Examples: OpenCCU App (runs the CCU software), File Editor, Terminal. Apps are NOT the same as integrations – OpenCCU App provides the backend, while Homematic(IP) Local is the integration that connects to it. (Note: "Add-on" was renamed to "App" in Home Assistant 2026.2.)

Plugin ⚠️¶

"Plugin" is not an official Home Assistant term. Please use "Integration" or "App" depending on what you mean. Using "Plugin" in bug reports causes confusion.

HACS (Home Assistant Community Store)¶

HACS is a community-maintained store for custom integrations, themes, and frontend components. Homematic(IP) Local can be installed via HACS. Important: Updates installed via HACS must also be updated via HACS.

Homematic Terms¶

Backend¶

The central control unit that manages Homematic devices. This can be a CCU3, CCU2, OpenCCU, Debmatic, or Homegear installation. The backend communicates with devices via radio protocols and provides interfaces (XML-RPC, JSON-RPC) that the integration uses.

CCU (Central Control Unit)¶

The official Homematic central unit hardware/software. CCU3 is the current model, CCU2 is the predecessor. OpenCCU, piVCCU/Debmatic are open-source alternatives running the same software.

OpenCCU¶

Open-source implementation of the CCU software, typically run on Raspberry Pi or as a virtual machine. Can also run as a Home Assistant App.

piVCCU / Debmatic¶

Open-source CCU implementations for Debian-based systems. piVCCU runs as a virtualized CCU, Debmatic runs natively on Debian/Ubuntu. Both use the official CCU firmware.

Interface¶

A communication channel to a specific type of Homematic device. Common interfaces:

• HmIP-RF: Homematic IP devices (wireless)
• BidCos-RF: Classic Homematic devices (wireless)
• HmIP-Wired / BidCos-Wired: Wired Homematic devices
• VirtualDevices / CUxD: Virtual devices and USB device extensions
• Groups: Heating groups configured in the CCU

Device¶

A physical or virtual Homematic device (e.g., thermostat, switch, sensor). Each device has a unique address and contains one or more channels.

Channel¶

A logical unit within a device that groups related functionality. For example, a 2-gang switch has two switch channels. Channel 0 is typically the maintenance channel containing device-level information.

Parameter¶

A named value on a channel that can be read, written, or both. Parameters are organized in paramsets (VALUES for runtime values, MASTER for configuration).

Data Point (Entity)¶

The representation of a parameter in Home Assistant. Each parameter becomes an entity (sensor, switch, climate, etc.) that can be used in automations and dashboards.

System Variable (Sysvar)¶

A variable stored on the CCU that can be used in CCU programs and accessed from Home Assistant. System variables appear as entities in the integration.

Program¶

A script or automation stored on the CCU. Programs can be triggered from Home Assistant using the integration's services.

Technical Terms¶

XML-RPC / JSON-RPC¶

Communication protocols used to exchange data between Home Assistant and the CCU backend. XML-RPC is the traditional protocol, JSON-RPC is used for some operations like fetching system variables.

Callback¶

A mechanism where the CCU sends events (value changes, alarms) back to Home Assistant. Requires proper network configuration so the CCU can reach Home Assistant.

TLS (Transport Layer Security)¶

Encryption for communication between Home Assistant and the CCU. Can be enabled in the integration configuration for secure connections.

Troubleshooting Terms¶

Diagnostics¶

A downloadable file containing configuration and state information about the integration. Essential for bug reports. Download via Settings → Devices & Services → Homematic(IP) Local → 3 dots → Download Diagnostics.

Protocol / Log¶

The Home Assistant log file containing messages from the integration. Found at Settings → System → Logs. Important: Only enable DEBUG logging when requested by developers.

Quick Reference¶