Frequently Asked Questions

The OPC .NET Client Toolkit is a development tool designed to implement and build OPC client applications using C# or VB.NET. It enables developers to access real-time data, historical data, and alarms and events from OPC servers, supporting key OPC specifications, which are DA, HDA, and AE.

OPC Easy Archiver is an OPC Client that supports OPC Classic DA, HDA and A&E specifications. It is designed to collect OPC real-time data, alarms messages and historical data records and archive them in SQL-like databases or into CSV files.

OPCNet Broker (ONB) is an OPC tunneling software used to establish remote OPC communication in OPC Classic environments in a secure way. It eliminates the complexities of DCOM configuration required by OPC legacy systems.

The OPC UA Client Toolkit is a robust and optimized .NET library that allows system integrators, developers, OEM and even end users to rapidly develop their own OPC UA Client applications using C# and VB .NET .

OPC UA Wrapper is a plug and play software product that enables users to easily migrate to OPC UA. It includes 2 components:

1. The wrapper, to allow OPC UA clients to communicate with OPC Classic servers. It supports OPC Data Access, OPC Historical Data Access and OPC Alarms & Events servers.
2. The proxy, to allow OPC Classic clients to communicate with OPC UA servers. It supports OPC UA DA, HA and AC capabilities.

An OPC UA Client is a tool that communicates with OPC UA Servers to retrieve, monitor, and update data. We provide a free OPC UA Client tool allowing users to test their OPC UA communications without restriction.

Make sure to configure the OPC Easy Archiver service logon with a user account that has privileges to connect to and read data from your OPC Server. To do so, proceed as follows:

1. Open Windows Services.
2. Locate the “Integration Objects' OPC EasyArchiver DA Service” service.
3. Right click on it and select Properties from the displayed menu.
4. Go to the Log On tab and select the option “This account”.
5. Enter the credentials of the correct user account.
6. Restart the service.

The OPC UA Server Simulator - Full Edition supports data access and historical access information models. These allow clients to access real-time and historical data, which is vital for testing OPC UA communications.

The OPC UA Proxy is a feature component of the OPC UA Wrapper. It allows converting an OPC UA Server to an OPC Classic Server and consequently establishing communications between OPC Classic Clients and OPC UA Servers.

Key features are:

1. OPC Data Access: Easily connect and communicate with OPC Data Access (DA) servers for real-time data monitoring.
2. Historical Data Access: Retrieve historical data from OPC servers with ease, making it simple to analyze trends and past performance.
3. Alarms & Events Access: Easily connect and communicate with OPC AE servers and retrieve alarm and event messages in real-time
4. Easy Integration: The toolkit is designed to integrate easily with any .NET application, reducing development time.

OPC Classic DA (Data Access), A&E (Alarms & Events), and HDA (Historical Data Access) communications are based on COM and DCOM technology. Indeed, OPC clients and servers use DCOM for the remote communications across a network. To achieve this, OPC Classic relies on a well-configured DCOM. This includes setting Windows security and firewalls, access control lists, server identities, etc. Without a well-configured DCOM, OPC Classic remote communications may not be established as expected and the required troubleshooting and fixes are usually challenging for end users. In addition, DCOM is a well-known technology and often targeted by hackers and it, consequently, has known security vulnerabilities that were actively exploited.

To get rid of DCOM configuration issues and security vulnerabilities, OPCNet Broker offers a more modern, safe, and user-friendly alternative to establish OPC remote communications in a secure tunnel using a single TCP port as well as data encryption to ensure data integrity and confidentiality. OPCNet Broker is considered a better and more secure alternative to DCOM for OPC communications.

An OPC UA SDK, short for “Software Development Kit,” is a collection of software tools designed to help developers create applications that use the OPC UA protocol. The SDK simplifies the process of implementing OPC UA clients and servers by providing pre-built functions and templates. The OPC UA Client Toolkit is an OPC UA SDK.

Users can configure their own tags and data simulation through CSV files. This allows for customizable and flexible simulation environments tailored to user specific testing needs.

The OPC UA Client supports the main OPC Unified Architecture models: Data Access, Alarms & Conditions, and Historical Access. Meaning, the OPC UA Client allows access to real-time data, alarms & conditions, and historical data from any compliant OPC UA server. It can monitor ongoing events and retrieve past information stored in the server.

The OPC .NET Client Toolkit is designed to be user-friendly, with comprehensive documentation and examples that guide you through the integration process. It simplifies the use of OPC in .NET applications, making it accessible even for developers who are new to the OPC standard.

The OPC .NET Client Toolkit is compliant with the following OPC standard specifications:

1. OPC Data Access 1.10, 2.05 and 3.00
2. OPC Historical Data Access 1.20
3. OPC Alarms and Events 1.10

OPC Easy Archiver supports Microsoft SQL Server, Oracle, MySQL, PostgreSQL, Microsoft Access, as well as CSV files. It connects to these databases via native drivers but also offers connectivity options via OLEDB and ODBC drivers.

Setting up DCOM can take hours to days, even without a firewall between the OPC Client and Server machines and may require extensive troubleshooting, while the installation and configuration of the ONB tunnel is an easy and quick set-up, with only a few clicks needed, and takes a few minutes only.

The OPC UA Client Toolkit benefits include:

1. Reduce the cost of ownership
2. Faster migration to OPC UA
3. Reduce cyber security vulnerabilities associated with legacy communications such as Modbus or DCOM/OPC

The OPC UA Wrapper license is a license per machine. License prices depend on the selected features. The available features are:

1. OPC DA to OPC UA Wrapper
2. OPC HDA to OPC UA Wrapper
3. OPC AE to OPC UA Wrapper
4. OPC UA to OPC DA Proxy
5. OPC UA to OPC HDA Proxy
6. OPC UA to OPC AE Proxy

An OPC UA Server provides and manages the data. An OPC UA Client requests and accesses data from an OPC UA Server . The client consumes the data while the server supplies and organizes it.

The OPC UA Client can discover OPC UA servers using OPC UA discovery server service.

OPC Easy Archiver supports Windows XP SP3, 7, 8, 10, and 11 and Windows Server 2003 SP2, 2008, 2008 R2, 2012, 2012 R2, 2016, 2019, 2022 and 2025.

OPCNet Broker provides secure, reliable, and efficient access to real-time data, historical records, alarms, and events. It enhances security and reliability of communications and data by:

1. Tracking of client/server communications,
2. Tunneling across firewalls through single ports to minimize security holes and Network Address Translators (NAT),
3. Connecting OPC Classic components from different domains, across VPN and through WANs and LANs,
4. User authentication at the server and tag levels for increased security,
5. Automatic reconnection when the connection is lost,
6. Configurable communication timeouts,
7. Data encryption for security reasons,
8. Data compression for better performance of data transfers across the network.

The OPC UA Client Toolkit supports the following operating systems:

1. Windows 11
2. Windows 10
3. Windows 8
4. Windows 7
5. Windows Server 2022
6. Windows Server 2019
7. Windows Server 2016
8. Windows Server 2012
9. Windows Server 2008

Yes, the OPC UA Wrapper can expose OPC historical data from OPC Classic HDA Servers to an OPC UA interface. This capability is especially critical for applications that need to analyze historical performance, track trends, and store data for an extended period but still depend on legacy OT systems. Users can use historical data to make informed decisions based on past trends and patterns.

Is there a free version of the OPC UA Server Simulator available? We do provide a free edition of the OPC UA Server Simulator, which is available here. The free edition supports 48 hours runtime. Meaning, it runs without interruption for 48 hours. You will have to restart it after 48 hours in order to continue using the simulator.

The OPC .NET Client Toolkit is compatible with the latest versions of the .NET framework, including .NET Core (3.1 or higher) and .NET Framework (4.6.1 or higher).

The OPC Easy Archiver allows you to connect to multiple OPC Servers. The OPC Easy Archiver license does not include limits on the number of connected servers or the number of tags.

OPCNet Broker simplifies your setup, ensures secure communication, improves communications reliability and reduces ownership cost.

The OPC UA Client Toolkit is licensed per development seat. Meaning, one license of the OPC UA Client Toolkit can be installed on a single development machine. With respect to runtime, you can deliver as many as you want for free.

The OPC UA Wrapper improves compatibility by serving as a bridge between OPC Classic servers and OPC UA clients and vice versa.

Yes.Users can configure multiple OPC UA Wrapper services to execute at the same time. It supports connections to numerous local and remote OPC (DA/HDA/AE) servers per service, as well as multiple OPC UA servers.

Yes, the full edition is designed to simulate real-time and historical data without interruption, making it a reliable tool for long-term testing and integration.

The OPC UA Client can establish secure communication channels using encryption and authentication. It generates a self-signed Application Instance Certificate to secure connections with OPC UA servers, ensuring data integrity and security.

Yes, OPC Easy Archiver can connect to and collect data from multiple local and remote OPC DA, HDA, and AE servers concurrently, enabling comprehensive data aggregation across various sources.

The OPC .NET Client Toolkit is designed for use with .NET environments and supports programming languages such as C# and VB .NET .

The OPCNet Broker (ONB) product includes 2 software components:

1. ONB Server Side to be deployed on the OPC Server machine
2. ONB Client Side to be deployed on the OPC Client machine

The toolkit supports .NET Core version 3.1 or higher as well as .NET Framework version 4.6.1 or higher.

The simulator supports the following data types:

1. Int16
2. Int32
3. Int64
4. UInt16
5. UInt32
6. UInt64
7. Double
8. String
9. Byte
10. Boolean

Yes, the OPC UA Client can monitor real-time data such as sensor readings and process values, as well as alarms and conditions, allowing users to respond to operational issues as they occur.

Yes, the OPC .NET Client Toolkit allows you to connect to and manage multiple OPC servers simultaneously. This feature is particularly useful for applications that require communication with more than one OPC server.

Yes, the OPC Easy Archivers includes features for continuous monitoring of connections and can automatically reconnect to OPC and database servers if the connection is lost, ensuring data collection continuity.

The OPCNet Broker license is a license per machine. License prices depend on the number of client and server machines as well as the selected OPC specifications (OPC DA, OPC HDA and/or OPC AE) per license. The first OPC Tunneller (ONB) installation will require a minimum of one client license and one server license.

The OPC UA Client Toolkit is licensed per development machine. You do not need a license in the runtime machines. Make sure to follow the instructions available on the user guide on how to deploy your application in the runtime machines.

The OPC UA Wrapper traces its operations via log files allowing users to effectively monitor system activities and troubleshoot issues if needed.

The OPC UA Client can explore and update historical data, giving users the ability to query past information for analysis or make changes to stored data when necessary.

The OPC UA Client Toolkit supports OPC UA specifications and the OPC .NET Client Toolkits supports OPC Classic DA, HDA and AE specifications.

The OPC Easy Archiver license is a license per machine. The license prices depend on the selected OPC specifications and databases connectors:

Supported OPC Specifications:

1. OPC DA
2. OPC HDA
3. OPC AE

Supported Database Connectors:

1. MS SQL Server
2. MySQL
3. PostgreSQL
4. Oracle
5. MS Access
6. ODBC
7. OLEDB
8. CSV files

OPCNet Broker supports:

1. OPC Data Access Specifications version 2.05a/3.0
2. OPC Historical Data Access Specifications version 1.1/1.2
3. OPC Alarms and Events Specifications version 1.10

We provide source codes of sample OPC UA Client applications with the OPC UA Client Toolkit. The related projects are available with the toolkit installation package. These sample projects enable users to get started on their applications development and understand how to use the toolkit.

The OPC UA Wrapper supports the following Windows OS versions:

1. Windows 7
2. Windows 8
3. Windows 10
4. Windows 11
5. Windows Server 2012
6. Windows Server 2016
7. Windows Server 2008
8. Windows Server 2019
9. Windows Server 2022

What are the prerequisites needed to install the OPC UA Client? Make sure that you have the following prerequisites available in your target machine:

1. .NET Framework version 4. 6 or higher.
2. The OPC UA Local Discovery Server, which lists the OPC UA endpoints available on a given computer. You can deploy it during the installation by checking the option “Install OPC UA Local Discovery Server” or after installation by using the setup available in the installation folder of the OPC UA Client. The OPC UA Client can explore and update historical data, giving users the ability to query past information for analysis or make changes to stored data when necessary.

Yes, you can use the OPC UA Client Toolkit to develop your application as Windows service.

The OPC UA Wrapper supports two types of OPC UA communication protocols: TCP and the HTTPS transport protocol for the proxy feature

By registering on our website, you can download a free 30-day trial license of OPC .Net Client from here for your test and evaluation purposes.

The OPC Easy Archiver license is a perpetual license. Only customer service support is renewable on a yearly basis upon user’s request.

Yes, OPCNet Broker AE supports alarm acknowledgement.

Yes, the OPC UA Client allows you to call OPC UA methods implemented in your OPC UA Server.The OPC UA Client can explore and update historical data, giving users the ability to query past information for analysis or make changes to stored data when necessary.

The OPC UA Client Toolkit supports Visual Studio 2017 and higher.

Yes, the OPC .NET Client Toolkit supports 32-bit and 64-bit applications.

Yes, the OPC Easy Archiver can store the collected OPC data into Azure SQL database.

OPCNet Broker is compatible with:

1. Windows Seven
2. Windows Server 2008
3. Windows 8
4. Windows XP
5. Windows Server 2003
6. Windows Server 2012
7. Windows 10
8. Windows Server 2016
9. Windows Server 2019
10. Windows Server 2022
11. Windows 11
12. Windows Server 2025

The OPC UA Wrapper does not include a limit on the number of tags or the number of connected OPC Servers.

Yes. You only need to set the current directory to the directory where your application files are located in order to load the required files of the OPC Client application. This is because the current directory of a Windows service is set to “.:\WINDOWS\system32” by default. To do so, verify the following items to be able to run the OPC Client Sample as Windows service:

1. Add the line below before initializing the OPCDAManager/OPCHDAManager/OPCAEManager:
2. Directory.SetCurrentDirectory(AppDomain.CurrentDomain.BaseDirectory);
3. Verify that you are running your OPC Client application service with a user account that has access rights to connect to the OPC Server and read data

By registering on our website, you can download a free 30-day trial license of OPC Easy Archiver for your evaluation and testing purposes.

When network connections are interrupted, OPCNet Broker:

1. Supports automatic reconnection capability. Meaning, ONB Client will try to reconnect to the ONB Server in a continuous basis until network communications are reestablished.
2. Supports OPC automatic reconnection capability. When this capability is enabled, ONB will try to reconnect to the disconnected OPC Server (s) in a continuous basis and without requiring a user intervention.
3. Uses a message queue to store unsent data until the connection is restored. This ensures that no messages are lost, and constraints can be applied to manage the size and number of queued messages.

Yes, the OPC UA Client Toolkit supports 32- and 64-bit applications.

You do not need Internet access to activate your license. After installing the OPC UA Wrapper, you will have access to the license authorization tool. Using this tool, you will be able generate a User ID code. Then, you will only have to send us this code so we can generate the activation code for you.

The OPC .NET Client toolkit is licensed per development machine. With respect to runtime, you can deliver as many as you want for free.

License prices depend on the selected OPC Specifications: DA, HDA and/or A&E.

To support OPC UA, you combine the OPC Easy Archiver with the OPC UA Proxy, which is a feature component of the OPC UA Wrapper. A tutorial video on how to configure and use the OPC UA Proxy is also available from here.

Yes. OPCNet Broker requires only one TCP port to be opened, making firewall rules configuration straightforward.

The OPC UA Client Toolkit supports OPC UA specifications and the OPC .NET Client Toolkits supports OPC Classic DA, HDA and AE specifications.

Prior to installing the OPC UA Wrapper, make sure that you have the following prerequisites available on your target machine:

1. OPC core components version 3.00
2. .NET framework version 4.0 or higher
3. OPC UA Discovery Server service
4. Visual C++ Redistributable (x86 and x64).

No. To load your configuration automatically at server start-up, make sure to set up your default configuration. To do so, please proceed as follows:

1. Click Save or Saved As button available in the File menu bar to save your configuration:
2. Name your configuration and save it as .oda file.
3. Click Define button available in the File menu bar.
4. Choose the configuration that you saved previously and click open.

A default configuration will be saved. This configuration will be loaded automatically whenever you restart the services (either manually or after machine restart).

By registering on our website, you can download a free 30-day trial license of OPCNet Broker for your evaluation and testing purposes.

When using the wrapper features, it is recommended to install the OPC UA Wrapper in the same machine as your OPC Classic Server in order to avoid DCOM.

When using the proxy features, it is recommended to install the OPC UA Proxy in the same machine as your OPC Classic Client in order to avoid DCOM.

To transfer your OPC Easy Archiver license from one machine to another, you will need to go through a license transfer process. This process involves removing the license from the old machine using a license remover tool and then activating the license on the new machine once the removal is confirmed. The main pre-requisite of this process is to have your support contract up-to-date.

Yes. Using ONB, you can configure an OPC tunnel between OPC Classic Servers and Clients belonging to different Windows domains, LAN, WAN, and even different sites as long as the used TCP port is allowed in the related firewalls and network equipment.

The OPC UA Proxy enables users to configure aliases for the tags via CSV files. The alias will define a friendly tag name of your choice and will be mapped to the original tag name e.g. unit/main.XXX[ns*2,s*unit/main.XXX].

Yes, users can configure rules to monitor critical tags or OPC server communications. Upon detecting these specific conditions in real-time, OPC Easy Archiver can perform automated actions such as sending email notifications, modifying data values, or starting and stopping archivers.

Certain OPC Classic Servers allow connections depending on user account privileges. In this case, make sure that the ONB Server service is running with a user account that has the right privileges to connect to and read data from your OPC Server as well as read/write access to the Windows Registry. To do so, please proceed as follows:

1. Open Windows Services.
2. Locate the “Integration Objects OPCNet Broker Server” service.
3. Right click on it and select Properties from the displayed menu.
4. Go to the Log On tab and select the option “This account”.
5. Enter the credentials of the correct user account.
6. Restart the OPCNet Broker Server service.

Yes, OPC Easy Archiver allows data transfer from database tables to OPC DA servers, facilitating seamless data integration.

Using the OPC Tag Security add-on for the ONB Server, you can define user access rights down to the individual tag level. This allows you to restrict third-party OPC Client applications to access specific tags within the OPC Server’s address space only. You can also deny write access to your tags. The OPC Tag Security add-on is licensed separately from the ONB Server.

Yes, it ensures the security of stored data by supporting encryption during data transfers and offering secure connection options for both OPC servers and databases. It also provides role-based access control and logging features to monitor system activity, helping maintain data confidentiality and integrity.

Yes, the ONB supports redundancy configurations to ensure high availability and minimize downtime on your communications and data flows. Redundancy can be configured between two ONB Server instances Primary and Secondary where the Secondary takes over in case the Primary becomes unavailable. You can also configure the switchover conditions on the client side to match your OPC Servers redundancy configuration.

They record error messages, debugging information, and other relevant data, allowing users to identify and resolve problems effectively. In normal operation, the client logs contain minimal information, but in case of difficulties, these logs provide critical insights into the underlying issues.

Yes, access to the ONB Client configuration tool can be restricted to prevent unauthorized changes. When this option is enabled, the ONB Client configuration tool is protected by a login and password to ensure the security of system settings.

The OPC Logger for CSV is a feature of OPC Easy Archiver that enables users to connect to multiple OPC DA and OPC HDA servers to retrieve real-time and historical data, respectively, and save this data into CSV files.

To support OPC UA, you can combine OPCNet Broker with our OPC UA Wrapper product. Refer here for more detail.

If you are encountering timeout errors while connecting to your OPC Server via ONB, you can adjust the timeout settings to improve communication reliability by increasing the “Invoc TimeOut “ and the “connection timeout”, as follows:

1. In the ONB Server Side:Stop the ONB Server service if it is already running
2. Open the ONB Server settings dialog.
3. In the Communication tab, set the Invoc TimeOut to 60000 ms
4. Save the new configuration and start the ONB Server service.
5. In the ONB Client Side:Stop all OPC Client applications.
6. Open the ONB Client Configuration Tool.
7. Right click on the ONB Connection node and select Communication Settings from the displayed menu.
8. Set theInvoc TimeOut to 60000 ms and save the new configuration.
9. Expand the ONB Connection node and select your OPC DA Server from the displayed menu.
10. Set the “Connection TimeOut” from “2000” ms to “30000” ms then save the new configuration.

Yes, it supports both synchronous and asynchronous data reads and writes for OPC DA servers, as well as synchronous and asynchronous reads and updates for OPC HDA servers.

Yes, it has the capability to operate as a Windows service, enabling it to run in the background and start automatically with the operating system start-up, ensuring continuous operation without user intervention.

To transfer your ONB Server or Client license from one machine to another, you will need to go through a license transfer process. This process involves removing the license from the old machine using a license remover tool and then activating the license on the new machine once the removal is confirmed. The main pre-requisite of this process is to have your support contract up-to-date.

The ONB Client Configuration Tool allows users to change the OPC Server ProgID automatically generated. You can proceed to the following instructions to correctly change the server ProgID in ONB:

1. Stop all open OPC Client applications.
2. Right click on the ONB Client Configuration Tool and select “Run as administrator” from the displayed menu
3. Select your configured ONB connection.
4. Modify your ProgID in the “Server Name” field displayed on the right side then click “Save”.
5. Click “Yes” and then “OK” to the prompted confirmation message boxes.

Yes. The OPC Easy Archiver includes 2 software components:

1. A graphical user interface allowing users to configure the OPC Servers connection, the OPC items, the subscriptions and the archivers.
2. Services that run in background to guarantee the continuity of the data collection and archiving.

You only need to specify a default configuration to be loaded automatically at service start-up.

The OPC Easy Archiver supports the following standard OPC specification versions:

1. OPC Data Access 1.0a.
2. OPC Data Access 2.00.
3. OPC Data Access 2.05a.
4. OPC Data Access 3.00.
5. OPC Historical Data Access 1.00.
6. OPC Historical Data Access 1.10.
7. OPC Historical Data Access 1.20.
8. OPC Alarms and Events 1.00.
9. OPC Alarms and Events 1.01.
10. OPC Alarms and Events 1.02.
11. OPC Alarms and Events 1.10.

If you notice that the OPC Easy Archiver reconnects to OPC AE server while you do not have a communication issue, this is because the OPC Easy Archiver also monitors the received alarms and events and initiates an automatic reconnection when no alarm has been received after a configurable period. Refer to the AE settings dialog to disable this behavior or adjust the timeout parameter.

To enable the OPC remote communications, you need to configure DCOM between the OPC client and server machines. Connection problems can be caused by DCOM misconfiguration or misconfiguration of the user logon of the OPC Easy Archiver services. Click here for more details and guidelines about DCOM configuration for OPC.

You need to first make sure that the OPC Easy Archiver service is running with the same user account used to run the OPC DA Explorer. If this does not resolve the connection failure, some OPC Servers that are 32-bit work only with 32-bit OPC clients. If you are using OPC Easy Archiver 64-bit version, try the following:

1. Uninstall the OPC Easy Archiver.
2. Restart the machine.
3. Reinstall the OPC Easy Archiver using an administrator account.
4. The installation wizard will take you through the different steps. When reaching the Runtime Mode dialog, select the “32-bit version” option.
5. Configure the OPC Easy Archiver service logon with the user account that is launching the OPC DA Explorer.
6. Redo your connection test.

The OPC Easy Archiver buffers the collected OPC data upon communication loss with the database servers and automatically transfers them after successful reconnection. This ensures store and forward capability.

Using the OPC Easy Archiver, you can filter retrieved alarms and events according to several criteria, which are:

1. Filter by Event Type.
2. Filter by Severity.
3. Filter by Category.
4. Filter by Area.
5. Filter by Source.

To properly run the OPC Easy Archiver, the following software components on the target system need to be installed:

1. OPC Core Components
2. .NET framework version 4.0 or higher

When configuring OPC groups in the OPC Easy Archiver, you can specify one of the following 3 read modes:

1. OnDataChange (for OPC DA version 2.05 and higher): the data will be collected asynchronously on report by exception basis.
2. Synchronous: the data will be collected by performing periodic synchronous read operations to the server. There are two types of read source: DEVICE and CACHE.
3. Asynchronous (I/O 2.0): the data will be collected by performing periodic asynchronous read operations to an OPC DA version 2.0 or higher compliant server.