# Using the OPC UA Service

## Enabling the OPC UA Service

The OPC UA service is by default enabled on Franka robot FP3/FR3. To check if the feature is enabled on your robot go to Settings -> System -> Installed Features. If the list contains OPC UA the service is enabled and ready to be used.

Note

A manually disabled feature can be re-enabled in the Franka World. More information of how to install a feature can be found in the Franka World Manual.

## Connect to and browse the OPC UA Server

This documentation explains how to connect to the robot’s OPC UA server and access its functionality via the software uaExpert.

### Starting uaExpert

Main screen of uaExpert after startup

The general user interface of uaExpert consists of several areas. The most important areas for browsing the OPC UA server of Franka robots, are the following:

Area Name | Description
--- | ---
Project | Shows all OPC UA servers that have been configured
Address Space | Shows the hierarchy tree with all items, that the OPC UA server provides
Attributes | Shows the detailed settings of the currently selected item in the address space area
Log | Shows log messages

### Creating a new Server and Connecting to it

First, you need to add the OPC UA server of the robot. In order to do that, select Server / Add from the menu bar.

Adding a new server

You need to fill out the input fields, as in the example image above. If you are running the OPC UA service as a feature of the robot, the Endpoint URL will be the IP address of the robot. If you are running the OPC UA service externally, use the IP adress of the device which is running the service. The default OPC UA port is 4840. UAExpert should use this port by default if you do not specify any particular port.

As username and password, you have to use the username and password which you use when logging in to the robot with your webbrowser via `robot.franka.de`.

Please be aware, that currently the password is not encrypted and will be transmitted in plain text.

### Browsing the OPC UA server

After successful connection, all items of the OPC UA server are hierarchically displayed in the Address Space area. You can click on items to expand and inspect them.

Browsing the OPC UA Server

Right click on method items and select Call from the context menu to call them. Doing so will display a new window, in which you can configure the input arguments to the method call. After clicking the Call button, the output results will be shown in the same window.

Calling a method with uaExpert and inspecting the return value