OPC Unified Architecture (UA) Server Interface

Included with KEPServerEX, no purchase necessary.
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Product Overview

The OPC Unified Architecture (UA) Server Interface for KEPServerEX provides client applications (such as MES and SCADA systems) seamless and secure access to industrial automation data.

OPC UA is a modern communications protocol for industrial automation that is increasingly being adopted for data collection and control by traditional on-premises applications and Industrial IoT and Industry 4.0 applications and platforms. It is an open standard, and allows the KEPServerEX OPC UA Server Interface to seamlessly connect to OPC UA client applications running on any operating system as well as web-based clients.

OPC UA offers built-in security through the use of certificate exchange and point-to-point encryption methodologies. With enhanced diagnostics capabilities for OPC UA, KEPServerEX keeps your data safe and enables you to easily troubleshoot client and server communication issues.

The OPC UA Server Interface can be used with the OPC UA Client driver to securely tunnel industrial data to a traditional OPC Data Access (DA) client or any native client interface supported by KEPServerEX.



  • Certified as a UA 1.02 Standard Server by the OPC Foundation's Certification Test Lab
  • Regularly tested against leading OPC client software at OPC Interoperability Workshops
  • OPC UA security and data integrity features, including Transport Layer Security (TLS) for data encryption, certificate-based authentication through x509 certificates and basic authentication using username/password
  • Supports up to 128 simultaneous client connections
  • Features a browsable namespace to enable the OPC UA client to easily identify data points to monitor
  • Provides advanced diagnostics for robust troubleshooting within KEPServerEX
  • Supports OPC tunneling for OPC DA 1.0 and 2.05a servers, which can also provide remote access for OPC DA clients and other native client interfaces supported by KEPServerEX
  • Works within the corporate network, over VPNs, through firewalls and across the internet, WAN or LAN
  • Supports data transfer frequency using a regular poll interval or Report by Exception on data change

Release Notes



  • Fixed a thread management issue that could result in a crash on some systems.
  • Resolved an issue where the server could crash due to a socket closing while in use.
  • Fixed an issue where the server reported BadSequenceNumberInvalid if the initial SequenceNumber was 1023.



  • Added new OPC UA Security Policy (Basic256Sha256) for server endpoint definitions. 
  • Updated the default Endpoint Security Policy to (Basic256Sha256) by default. 
  • SecurityLevel for deprecated Policies in GetEndpointsResponse is now 0. 
  • Added Event Log message to warn user when the server fails to start due to an invalid certificate. 



  • Resolved an issue where groups and tags that shared a name and parent could not be browsed by clients or added to the server.



  • Fixed an issue where NodeIds with multiple semicolons in the string would fail to parse correctly.
  • Fixed an issue where clients that set AnonymousIdentityToken with a NULL PolicyId were rejected with a status of Status_BadIdentityTokenInvalid.
  • Fixed an issue where the UA communications could fail to reconnect after either a closed session or closed socket connection caused by setting the system clock forward or backward in time.

Use Case: Failsafe Controls

In the highly competitive Oil and Gas Industry, the need for timely and accurate field data is critical. Optimizing production, planning future drilling and managing well reserves and spot gas supplies are more important than ever. Failsafe Controls is making the best-informed business decisions while saving their customers money in the process by using cutting-edge process control and automation technology for its customers.

Failsafe Controls' customer, an oil and gas exploration and production company, embarked on a huge automation initiative to bring their outsourced process control and data acquisition management operations in-house. They turned to the experts in the field—Louisiana-based Failsafe Controls—to help them develop a fully integrated, web-enabled production automation system that allows real-time and accumulated data from each well to be accessed by key personnel: field operators, engineering, gas/data gathering teams and regional/executive management. By empowering all teams and departments with the ability to recognize trends and identify any problematic areas, production levels can be continuously optimized.

Read the full case study

KEPServerEX is more than an OPC server—it's a connectivity platform for industrial automation and IoT. Simply download KEPServerEX, and then select from Kepware's library of more than 150 device drivers, client drivers, and advanced plug-ins to fit the communication requirements unique to your industrial control system.

A feature is an integrated software component of KEPServerEX that provides additional core server functionality. Features are included with the purchase of any KEPServerEX license, and can be utilized at any time.