---
title: Use the OPC UA Client Advanced driver for OPC UA Alarms & Events
slug: litmusedge/use-the-opc-ua-client-advanced-driver-for-opc-ua-alarms-and-events
docTags: 
createdAt: 2025-02-05T16:37:26.739Z
---

:::hint{type="info"}
**Note: **This feature is available from Litmus Edge *3.16.2 *release.
:::

You can use the OPC UA Client Advanced driver in Litmus Edge to browse, integrate, and manage OPC UA Alarms & Events (A\&E). 

These events are imported as tags within your device configuration and can be customized to include specific event properties. This includes attributes such as **EventType**, **Message**, **Severity**, **ReceiveTime**, **EventId**, **SourceName**, **SourceNode**, and more.

# Before You Start

Make sure you meet the following prerequisites before configuring your device:

- A stable network connection between your Litmus Edge device and the OPC UA server to send alarms and events data.
- Your OPC UA login details, including authentication tokens or certificates.

# Use the OPC UA Client Advanced for OPC UA Alarms & Events

Follow the steps below to add an *OPC UA Client Advanced* device, browse event tags, and view the event data using the *Analytics DataHub Subscribe *function node.

# Step 1: Add OPC UA Client Advanced Device to DeviceHub

1. In Litmus Edge, navigate to **DeviceHub **> **Devices**.
2. Click the **Connect a Device** box.
   The *Connect Device *dialog box appears.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/atJL37pPuLGI2bM_w2ibz_adddevice.png" size="80" width="1046" height="528" caption="Connect a Device box" position="center" showCaption="true"}
3. In the **Driver Name** drop-down list, select **OPC UA **> **OPC UA Client Advanced**.
4. Configure the parameters for the device. 
   See [Connect a Device](docId\:pal6ABPZbrimdU9LvGJ30) and [OPC UA](docId\:Dt3Sz4V-_0_t-GQnPURoh) or [OPC UA Client Advanced](docId\:dymfNqY-4gQlrykF0ckey) to learn more.

# Step 2: Set Up the OPC UA Client Advanced Browse Tags

1. In **DeviceHub**, click on the *OPC UA Client Advanced* device you just added.
2. Navigate to *Tags *section and click the **Add Tag (+)** icon. 
   - Select **Browse Tags **to open the *Browse Parameters *dialog box.
     ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/miYXM0FZlgc98u4v0KA3L_image.png" size="80" width="1872" height="717" position="center" caption="Tags section" showCaption="true"}
3. Choose between two options for *Browse Mode*:
   - **Data Access:** For accessing real-time data variables.
   - **Events:** To monitor alarms and conditions. For this guide, select **Events**.
   - Click **Apply parameters** to open the OPC UA server’s tag tree for exploration.
     ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/2uxLXW4RBr7lBVuf5rjd0_image.png" size="50" width="502" height="277" position="center" caption="Browse Parameters dialog box" showCaption="true"}
4. Expand the tag tree to find the events you want to track (e.g., *Alarms & Conditions*).
5. Select the desired alarms/events from the tree structure and click **Add **to include them as tags.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/By8as4m5hHn71JzAerCxL_image.png" size="70" width="1223" height="687" position="center" showCaption="false"}

:::hint{type="info"}
## Important Note

Understanding the significance of the *Namespace Index *values linked to *Event Properties* is crucial when adding an OPC UA A\&E tag in Litmus Edge. The *Namespace Index *is mandatory for the unique identification of the event property within the OPC UA server's address space. Every OPC UA event property is distinctly identified by both its *Name *and *Namespace Index*.

### Finding the Namespace Index

To determine the correct *Namespace Index *for a specific event property beyond the default set, you may need to use an OPC UA client tool, such as *UaExpert*, to inspect the details of the events available from your OPC UA server. These tools typically display the *Namespace Index *associated with each property.

When you select an OPC UA A\&E tag, a standard set of event properties (such as *EventId*, *EventType*, *SourceNode*, *SourceName*, and *Time*) will be added by default to the tag configuration. These are defined by the OPC UA A\&E specification.

### Namespace Index Ordering Behavior

For nested and non-nested OPC UA event properties, the order of *Namespace Index* values affects Litmus Edge's responses. See [Manage Tags](docId\:qm0urCLtmYSiMHM2_5kMx) for more details.

::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/lzhbMFcgdZxfBn_CbrsAP_image.png" size="80" width="1254" height="763" position="center" caption="Edit Tag Dialog Box" showCaption="true"}
:::

# Step 3: Modify Event Properties in Edit Tag Dialog Box

To add or customize event properties beyond this default set, click the **Add Item** button within the *Edit Tag* dialog box. 

This will allow you to enter the **Namespace Index** and the **Event Property name** of the additional property you wish to include in the tag's payload.



:::hint{type="success"}
**Key Points: **

- Enter the correct *Namespace Index *value obtained from your OPC UA server information (potentially via a tool like *UaExpert*), and the precise name of the event property. Incorrect values will lead to incorrect or missing data.
- The OPC UA A\&E model defines a hierarchy of event types and their properties. Litmus Edge offers a standard set of commonly used properties, but not all OPC UA specification or custom extension event properties are shown in the **Edit Tag **view initially. This design prioritizes relevant information. 
- However, using the **Add Item** function and specifying the *Namespace Index *and *Event Property name *allows you to access and include additional properties in your data.
- While adding the **nested **and **non**-**nested **event properties, the ascending *Namespace Index* ordering is important as an incorrect sequence may lead to unresolved or missing nested data.
:::

**To add a custom event property:**

1. To add a custom event property which, upon inspection in your OPC UA client tool, has a *Namespace Index* of **1**.
2. In the *Edit Tag *dialog box, click the **Add Item** button.
3. In the *Namespace Index* field, enter **1**.
4. In the *Event Property name* field, enter a suitable name.
5. Click **Update Tag** to save your changes.

::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/hUfeKglfYaDRpfGKf2xhg_image.png" size="70" width="1264" height="624" position="center" showCaption="false"}

# Step 4: Enable the Connector

After adding the connector, click the **Start **icon in the connector tile to enable it. 

::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/f1R1uGsmKgZ1BZc7Lx38P_image.png" size="50" width="379" height="327" position="center" caption="OPC UA Client Advanced  connector tile " showCaption="true"}

If you see a *Failed *status, you can review the [Connector Logs](docId\:BEQQ0sSzwsv9v9rIF3rhk) and relevant error messages. 

# Step 4: Copy the Raw Topic

1. Click the *OPC UA Client Advanced *connector tile. 
2. Navigate to *Tags *section and click the **OPC UA** device in the side menu.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/YtlGvWj49va5sLtqWaCN4_image.png" size="80" width="1817" height="553" position="center" caption="Tags section" showCaption="true"}
3. Find the *Raw Topic* field in the tag details and click the **Copy **button to copy the topic.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/lz7548_oC9j-ZFnsivI_P_image.png" size="80" width="1426" height="272" position="center" caption="Tags section" showCaption="true"}
4. Save this topic somewhere safe. You'll need it to configure the *Analytics *node later.

# Step 5: Use Analytics to Verify the Data Transfer

1. In Litmus Edge, navigate to **Analytics**. 
2. On the analytics canvas, click** Add processor**. 
   The *Create a processor* dialog box displays. 
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/ZdcpDTjKPrLwdKeFw6LWq_base-conversionadd-processor.png" size="80" width="1244" height="452" caption="The Add processor option" position="center" showCaption="true"}
3. Select **DataHub Subscribe**.
4. In the *Topic *field, paste the **Raw Topic **you copied earlier from *Step 4*.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/AdCgZcKlrYLXkOnUTBkWY_a.png" size="80" width="1142" height="604" position="center" caption="Create a Processor dialog box" showCaption="true"}
5. Click **Save**.
6. On the analytics canvas, click **Save**.
   The configured analytics flows should look like the following:
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/5xY5eney18jzo4WAS-IQM_image.png" size="80" width="1180" height="202" position="center" caption="Completed Flows Canvas" showCaption="true"}
7. Click the **View **icon in the *DataHub Subscribe *processor to view the event data.

::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/KriqP_3kuL3avYrFmZk8e_image.png" size="80" width="1607" height="756" position="center" showCaption="false"}

Monitor the real-time event data published to the Litmus Edge message broker, which includes key-value fields such as `EventId`, `EventType`, `Message`, `ReceiveTime`, and `Severity`.