For details, see the OPC UA Safety test specification.

An exemplary test principle for OPC UA Safety is presented. The OPC UA Safety test is a fully automated verification based on test patterns covering all paths of the OPC UA Safety finite state machines. All kinds of possible correct and incorrect SPDUs, parameters, and interactions with the upper interface of the SafetyProvider / SafetyConsumer driver are taken into account. These test patterns together with the expected responses/stimulations are stored as an XML document and imported into the test tool software. The test tool executes the complete test patterns while connected to the OPC UA Safety layer under test, compares the nominal with the actual reactions and is recording the results that can be printed out for the test report.

The automated OPC UA Safety layer tester will be approved by a Notified Body.

Figure 25shows the structure of the layer tester for the SafetyProvider and SafetyConsumer.

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Figure 25– Automated SafetyProvider / SafetyConsumer test

The SafetyProvider / SafetyConsumer tester "simulates" the behavior of an opposite SafetyProvider / SafetyConsumer Layer. Thus, it must be configured according to the deployed OPC UA communication system. This can be done with the help of an XML file associated with the tester.

A so-called “upper tester” runs on top of the SafetyProvider or SafetyConsumer within the device under test (DUT). It transfers data from the SafetyProvider or SafetyConsumer via its SAPI and makes them visible to the test tool via an OPC UA interface that is specified in the OPC UA Safety test specification (“Set Data” in Figure 26and Figure 27). In a similar way, the upper tester enables the test-tool to set inputs of the SAPI (“Get Data” in Figure 26and Figure 27).

The upper tester is implemented by the vendor of the DUT using standard program languages such as C/C++, IEC 61131-3 or Structured Text and does not need to be executed in a safety-related way.

Detailed requirements for the upper tester are described in the OPC UA Safety test specification.

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Figure 26–"Upper Tester" within the SafetyProvider

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Figure 27–"Upper Tester" within the SafetyConsumer