Browse frequently asked questions grouped by topic. Click a heading to open its answer.
Kepware Server
Can Kepware Server communicate with Siemens Sinumerik CNC machines?
Yes. Kepware Server offers dedicated driver support for Siemens Sinumerik CNC controllers. Contact our support team for detailed compatibility information.
Is there a product called KEPServerEX? What is it called now?
The KEPServerEX name has been retired. The product continues as Kepware Server under Velotic (formerly KEPServerEX). It keeps the same core architecture; the current release line is 7.0.
Siemens device protocol error [Class=0x81, Code=0x04]
This error usually occurs due to an incorrectly defined device address or incompatible communication parameters. Check the addressing rules in the driver documentation; open a support ticket if the problem persists.
Central access for multiple Kepware Server installations
To manage multiple Kepware Server installations from a single client, use the Configuration API or secure connections with OPC UA certificates. For enterprise-scale deployments, the cloud-based Kepware+ Manager provides centralized monitoring and configuration.
The license transfer option is not active on virtual machines
This is usually because the license is bound to a physical machine. You need to perform a license transfer (activation) through the My Kepware portal to work in a virtual environment. See our licensing page for details.
BACnet Protocol Implementation Conformance in Kepware
The BACnet driver provides connectivity to building automation devices over BACnet/IP. Configuration should be made according to the capabilities in your device's PICS document.
Which OPC UA features does Kepware Server support?
Kepware Server can act as both an OPC UA server and client. On the server side it exposes data to UA clients; the OPC UA Client driver connects it to other OPC UA servers. Connections can be configured with certificate-based security and user authentication.
Kepware Server help documentation ↗ · Driver documentation ↗
Which port should be opened for OPC UA connections?
The default OPC UA TCP port for the Kepware OPC UA Server is 49320. The firewall must allow this port and the components needed for certificate exchange. The port can be changed in the settings for your deployment.
What is IoT Gateway? Does it support MQTT and Sparkplug B?
IoT Gateway is an advanced plug-in that sends Kepware Server data to MQTT-based publishers (brokers). It supports Sparkplug B and generic MQTT publishing profiles, so plant data can be carried securely to cloud and analytics platforms.
Which operating systems does Kepware Server 7.0 support?
Kepware Server 7.0 runs on 64-bit Windows versions; the 7.0 release line adds Windows Server 2025 support. 5.x versions are no longer supported; verify system compatibility in the official release notes before upgrading.
The OPC UA client reports an "Untrusted Certificate" error — how do I fix it?
The client does not trust the server's certificate (or vice versa). The fix is to add the peer's certificate to your trust list. In Kepware Server, certificate management happens in the OPC UA Configuration Manager: rejected clients are listed there and can be approved. In production, manage the trust list correctly instead of disabling certificate validation.
Kepware Server help (OPC UA settings) ↗ · Our security guide article ↗
Is connecting with SecurityPolicy=None secure?
No. SecurityPolicy=None leaves the channel unencrypted and unsigned; neither the data nor authentication is protected. Reserve this setting for isolated test networks only; in production choose Basic256Sha256 or a newer policy with the SignAndEncrypt mode.
Which user authentication methods does OPC UA support?
OPC UA defines three user token types: Anonymous (no identity), UserName (username + password) and Certificate (client user certificate). Defining permissions by role and keeping write/control rights on separate accounts is the most common best practice.
OPC Router
Does OPC Router require programming knowledge?
No. With OPC Router's drag-and-drop visual configuration you model data flows without coding; SAP, database, MES, printer and cloud connections are set up with ready-made plugins.
Which databases can OPC Router connect to?
Relational databases such as SQL Server, Oracle, MySQL and PostgreSQL, and NoSQL systems such as MongoDB and InfluxDB; plus other data sources via ODBC.
How do OPC Router and Kepware Server work together?
Kepware Server connects to field controllers and exposes the data over OPC UA; OPC Router receives it and distributes it bidirectionally to SAP, MES, databases, reporting and cloud systems. Together they form an end-to-end data backbone.
Which systems can OPC Router connect to?
OPC Router connects to many targets with ready-made plugins: OPC UA/OPC DA clients and servers, SAP, SQL databases (SQL Server, Oracle, PostgreSQL, MySQL), file and printer reporting, MQTT and REST-based services. See the product site for the current full list.
How does OPC Router communicate with Kepware Server?
OPC Router connects to Kepware Server as an OPC client: over OPC UA or OPC DA it accesses the tags collected on the server and routes them to targets such as SQL, MES and SAP. The flow between the two products is modelled with drag-and-drop connections, without code.
How does writing to a database work with OPC Router?
With the SQL plugin, OPC Router writes incoming data to the target table as insert or update statements; SQL Server, Oracle, PostgreSQL and MySQL are supported. Column mappings are defined visually; in complex flows data can be prepared first and written afterwards.
Routine Maintenance Tips
Maintenance recommendations
- Regular backups and version updates
- Periodic review of event logs
- Renewal of OPC UA certificates
- Reading the Migration Guide before upgrading to 7.0
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