---
title: Litmus OPC Fusion
slug: solutions/litmus-opc-fusion
docTags: 
createdAt: 2026-07-29T20:17:28.439Z
---

Connect your legacy OPC DA systems to Litmus Edge

## Prerequisites

- Windows 7 or later
- At least one OPC DA server installed and running (e.g., Kepware, Matrikon, RSLinx)
- Network access to target OPC DA servers
- Administrator privileges for installation
- Litmus Edge instance for final integration (optional for initial testing)

## Step 1: Install OPC Fusion

1. Download the OPC Fusion installer from the Central Portal.
2. Run OPCFusionSetup.exe as Administrator.
3. Accept the license agreement.
4. Choose installation directory (default: C:\Program Files\Litmus\OPC Fusion).
5. Select the components to install.
6. Verify the ports and modify as needed.
7. Click **Install.**
8. Wait for installation to complete.
9. Click **Finish.**

## Step 2: Start the Service

The OPC Fusion service starts automatically after installation if selected on the last page. Verify it's running or start it by:

**Option A: System Tray**

- Look for the OPC Fusion icon in the system tray
- Icon should be green (running)
- Right click on the icon and select Start Service if not running.

**Option B: Services Console**

1. Open Windows Services (services.msc)
2. Find "Litmus OPC Fusion Gateway"
3. Status should show "Running"
4. Right click on the service and choose Start if not running.

## Step 3: Access the Web UI

1. Open your web browser
2. Navigate to: http\://localhost:8443
3. Log in with default credentials:
   - Username: admin
   - Password: litmusfusion

![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/PCSWreFqmYmH4X3AOvQk4_login.jpg)

**Important**: Change the default password immediately after first login!

## Step 4: Add an OPC DA Server

1. Click **OPC DA** > **DA Clients** in the sidebar
2. Local servers should automatically be displayed in the Discover tab.  If the server is listed then click the **+ Add **button and proceed to step 5.
3. If need you can add a server manually by selecting the **Servers** tab clicking **+ Add Manually**
4. Fill in the connection details:
   - **Name**: A friendly name (e.g., "Kepware Server")
   - **ProgID**: The OPC server's ProgID (e.g., "Kepware.KEPServerEX.V6")
   - **Hostname**: localhost for local, or IP/hostname for remote
   - **Update Rate**: 1000 ms (default)
5. Click **Create**



![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/ecGk2_zu7s0DXpsi_1KTb_opcserver.jpg)

The server status should change from "Connecting..." to "Connected" within a few seconds.

## Step 5: Create Tag Mappings

1. Click the **Browse Tags** tab.
2. Select your DA server from the dropdown.
3. Click **Connect **to explore the server's address space.
4. Select a tag and click **Add.**
5. Repeat for additional tags.
6. Click **Add X Tags to Mappings **when complete.



![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/9-eOAzrja1Yaia5P8hBjC_mapping.jpg)

## Step 6: Test OPC UA Output

Before connecting Litmus Edge, verify OPC Fusion is working with a test OPC UA client:

**OPC Fusion Endpoint**:

- **Endpoint URL**: opc.tcp\://localhost:4840
- **Security Mode**: None (for initial testing)
- **Namespace**: ns=2 (default for mapped tags)

**Test Clients**:

- UaExpert (Unified Automation) - Recommended for testing
- Prosys OPC UA Browser



![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/t26m3AK7yjTJkF-jybbzc_uaexpert.jpg)

## Step 7: Connect Litmus Edge

Now connect Litmus Edge to OPC Fusion to bring your legacy DA data into the Litmus Edge platform:

1. Log in to your **Litmus Edge** instance
2. Navigate to **DeviceHub** > **Devices**
3. Click **+ Add Device**
4. Select **OPC UA Client Advanced** driver
5. Configure the connection:
   - **Name**: OPC Fusion Gateway
   - **Driver Mode**: Subscription
   - **Server URL**: opc.tcp\://\<opc-fusion-host>:4840
   - **Security Policy**: None (Not recommended for production\*)
   - **Security Mode**: None (Not recommended for production\*)
6. Click **Create Device**
7. Browse OPC Fusion's address space and select tags to import

![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/H592ohCAy0Yqr6T8Pwjhn_litmustags.jpg)

Your legacy OPC DA data is now flowing into Litmus Edge!

\*For production it is best to use secure communication and setup certificates&#x20;

## Step 7: Monitor Operation

In the sidebar visit:

1. **Dashboard** to see system overview
2. Click **Tags&#x20;**>**&#x20;Monitoring** to view real-time tag values
3. Click **System** > **Streaming Logs** to see operational logs

## Troubleshooting Quick Reference

| Problem                        | Solution                                         |
| ------------------------------ | ------------------------------------------------ |
| Service won't start            | Check Windows Event Log, run as Administrator    |
| DA server shows "Disconnected" | Verify ProgID, check DCOM settings               |
| Can't access Web UI            | Verify port 8443 is not in use                   |
| UA client can't connect        | Check firewall for port 4840                     |
| Tags not updating              | Verify DA subscription active, check update rate |

For detailed troubleshooting, see Troubleshooting Guide.

*Congratulations! You've successfully set up OPC Fusion.*