# Developing with the OPC UA Service

- Racecom API documentation
  - List of all Operations
  - Timeout
  - Read vs. Take
- OPC UA API documentation
  - Custom Data Types
  - OPC UA Server Address Space
  - Execution Control
  - Self Tests
- Simple Python Client Tutorial
  - 1. Install Python
  - 2. Install Pip
  - 3. Install FreeOpcUa / python-opcua
  - 4. Run the Sample Python Client
- Simple C++ Client Tutorial
- Simple C# Client Tutorial
  - 1. Install .NET and VSCode
  - 2. Create a C# console application
  - 3. Run the Sample C# Client
- Siemens S7-1500 Client Tutorial
  - Opening the project and first steps
  - Configuring the connection to the OPC UA server
  - Selecting variables and methods
  - Loading the project to the S7-1500
  - Starting the OPC UA connection and using the features
  - Current Limitations
  - Error Code Reference
- Beckhoff TwinCAT 3 Client Tutorial
  - Preconditions
  - Testing the connection to the OPC UA server (optional)
  - Configuring the connection to the OPC UA server
  - Selecting variables and methods
  - Loading the project and starting the OPC UA connection
  - Read variables and execute methods
  - Current Limitations

Note

Whatever method you choose to communicate to the OPC UA server, you should make sure to only open a connection once in the beginning and then keep that connection open for as long as you need it. Repeatedly opening and closing OPC UA connections can result in significantly worse performance.