Troubleshooting
Finding Errors in Configuration and Project Planning
Despite all precautions, there’s always a chance that a flow won’t “work.” In very rare cases, these are actual errors; more often than not, they are minor issues that can arise when connecting third-party systems. Below, we’ve compiled a list of common pitfalls—and we’re always grateful for any feedback or additional information.
Problems rarely occur when the router, OPC server, and database server are running on the same machine. In a distributed system, the correct DCOM configuration is important for the OPC server, while database servers themselves either allow or deny remote access.
In any case, be sure to use the tests provided in the management interface: “Check connection” for the database connection and “Test” for the mail server connection. The OPC connection works if you can browse the OPC servers in the management interface (see below). Note that the configuration and the service may run in different user contexts and therefore behave differently.
If the error occurs at runtime, you’ll need to use Web Management: The event log in the status display shows the recorded messages; you can download the log files via the menu; and if the recorded data isn’t sufficient, extend the logging period. This is described at Log Files and Event Log .
If a flow isn’t transferring any data at all, start with “” “Transfer isn’t running”: The page walks through the causes one by one and refers you to the appropriate section in this chapter.
The pages in this chapter
Get Started by Symptom
- Transfer Not Running – the starting point when a flow isn’t transferring data: seven checks ranging from pending publication to flow state, status tree, and triggers, all the way to logged messages.
- Transfer Without Error Message (Empty SELECT) – when transfers go unnoticed because a query returns no results.
By System
- OPC Classic connections – if the OPC server is unreachable or items remain empty: DCOM configuration, item names, and service permissions based on specific log messages.
- OPC UA Connections – if an OPC UA client connection cannot be established or data points do not return a valid value: security level, endpoint and certificate, status codes, redundancy server.
- Database Connections – if a local or remote database connection fails: remote access, missing tables, blocked stored procedures, anonymous login at runtime.
- MQTT Connections – if the connection to the broker fails or messages are not received: port and encryption, client ID, and the symptom tables for the three cloud profiles.
- SAP® Connections – if an SAP® connection cannot be established or IDocs and RFC calls do not arrive: Authorizations, port, SNC requirements, and feedback to the SAP® system.
Tools
- Diagnostic Report – if support needs documentation: project configuration, database backups, and log files as a ZIP package.
- Log Files and Event Log – where the log files are located, how to download them without access to the server, and how to enable logging.
- Re-enable Clipboard Access After Blocking – when the browser refuses to paste from the clipboard because permission was previously denied.
Redundancy Error Scenarios—Connection Test, Pre-shared Key, Version Mismatch—are covered in the Redundancy Troubleshooting section at in the Redundancy chapter.