OPC Server Connection Guide

Overview

The ATSCADA ecosystem provides exceptional flexibility for integrating data from third-party OPC Servers (such as KepServerEX) into a centralized data management architecture. Depending on the project scale and distributed system requirements, users can implement one of the following connection methods.

Direct Connection from the SCADA Application

This is the standard connection method, suitable for standalone or small-to-medium SCADA systems. In this architecture, iDriver—the core data management engine of ATSCADA—directly accesses the OPCClient.dll library to communicate with the OPC Server. This approach maximizes communication performance when both the SCADA application and the OPC Server are installed on the same local machine or network.

Distributed Connection via ATDriver Server Gateway

For large-scale distributed systems requiring remote monitoring and centralized data acquisition, ATSCADA uses ATDriver Server as an intermediate I/O Driver Server.

• Eliminates DCOM complexity: Traditional OPC DA communication relies on DCOM technology, which is often difficult and complex to configure across distributed computer networks.
• Modern communication architecture: ATSCADA overcomes these limitations by utilizing Windows Communication Foundation (WCF) and a service-based architecture built into ATDriver Server. The OPC Server communicates locally with ATDriver Server, which then securely distributes data to multiple SCADA applications over LAN or the Internet. This architecture provides transparent communication regardless of distance while ensuring high reliability and system security.

View more: Common ATSCADA Errors 

Demo Deployment Scenario

Demo Scenario for Both Connection Methods

• Device: One PLC (Siemens, Mitsubishi, or equivalent) connected to KepServerEX.
• Data Address: Register 40001 (Word data type).
• Control Logic: When the SCADA application writes the value 100 to this register, the PLC activates the buzzer and turns on two LED indicators on the demo station.

Preparation Requirements

• PLC: Prepare one PLC with the required demo program already installed. Connect the PLC to the computer running KepServerEX to create the necessary Tag Files.

• Control Logic: When the SCADA application writes the value 100 to register 40001, the PLC activates the buzzer and turns on two LED indicators on the demo station.

• OPC Server: Ensure that KEPServerEX (or an equivalent OPC Server) is installed and configured with the required Tag Files to read data from the PLC.

Technical Deployment Guide

Method A: Direct Connection from the SCADA Application (Using OPCClient.dll)

Import Tag Names from KEPServerEX Using iTagBuilder

1.Open iTagBuilder.

2.Click the Add New button on the toolbar.

3.In the dialog box, enter the Driver Name (for example, OPCServer).

4.Click Add Driver.

5.Select OPCClient.dll. This driver is used to import and manage tag definitions from the OPC Server.

 

6.A dialog will display the KEPServerEX instance running on the same computer as iTagBuilder. Select the server and click Connect.

 

7.Go to Tools → Import Group, then select the appropriate Tag Group that was previously configured in KEPServerEX.

 

 

You will see the Channel, Device, and Tags that were created in the previous step.

 

 

Click OK to import the Tags from KepServer into iTagBuilder

 

 

8. Go to File => Project Register or press the shortcut Ctrl+R to register TagFile.

 

Method B: Distributed Connection via ATDriver Server Gateway (Using OPCDAClient.dll)

1: Create a Channel

1. Open ATDriver Server.
2. Click the Add Channel button on the toolbar.
3. In the dialog box, enter a Channel Name (for example, ConnectToKepServer).
4. Under the Driver field, browse to and select OPCDAClient.dll.

5. A Channel Address dialog will automatically appear. Select the appropriate OPC Server running on the computer (for example, Kepware.KEPServerEX.V6) and click Apply.

2: Add a Device

1. Select the ConnectToKepServer channel you just created, then click the Add Device button.
2. Enter a Device Name (for example, Device1).
3. Configure the Update Rate (ms). This defines how often the system refreshes data. For local networks, an update rate of 100 ms is recommended. Click Apply.

3: Add Tags

1. Select the Device you just created, then click the Add Tag button.
2. The system will display the OPC Server Tree View. Browse to the appropriate Device and select the required Tags that were previously configured in KEPServerEX.

3. Select the Tag you want to import (for example, Tag1).
4. Under Data Type, select the appropriate data type (for example, Word, Double, or String) to match the data type configured in the OPC Server. Click Apply to complete the tag configuration.

Verify and Run the Sample Project

This section demonstrates how to build a common control interface that can be used with both connection methods.

Create a sample Desktop Application in Visual Studio to interact with the PLC data.

Use the iImagePos component to display different images based on the corresponding data values.

View more: ATSCADA Hospital Temperature and Humidity

.

And an iButton component to write the value 100 to the PLC register.

Test the application.

Now let’s try pressing the BUTTON to write the value 100 to the PLC on KepServerEX.

On the PLC, you will see two lights illuminated.

 Learn More about ATSCADA Software

view atscada demo & download

ATSCADA - Smart SCADA Software with AI Predictor & Blockchain. ATSCADA is an advanced SCADA software platform for real-time monitoring, intelligent control, and efficient data acquisition. It is ideal for Industrial IoT (IIoT), smart cities, integrated automation systems, and Agriculture 4.0. With a built-in AI Predictor, ATSCADA enables predictive analytics to detect issues early, optimize performance, and reduce downtime. The integration of Blockchain technology ensures secure, transparent, and tamper-proof data management. Highly scalable and easy to integrate, ATSCADA is trusted by businesses to enhance productivity, strengthen cybersecurity, and accelerate digital transformation.