6 Information Models ToC Previous Next

This chapter describes the identifiers, types and structure of the objects and methods that are used to implement the OPC UA mappers defined in this part. This implementation serves three purposes:

  • support of the safe exchange of SPDUs at runtime
  • online browsing, to identify SafetyConsumers and SafetyProviders, and to check their parameters for diagnostic purposes
  • offline engineering: the information model of one controller can be exported in a standardized file on its engineering system, be imported in another engineering system, and finally deployed on another controller. This allows for a vendor-independent exchange of the communication interfaces of safety applications, e.g., for establishing connections between devices. IMPORTANT NOTE:

Neither online browsing nor offline engineering currently supports any features to detect errors. Hence, no guarantees with respect to functional safety are made. This means that online browsing can only be used for diagnostic purposes, and not for exchanging safety-relevant data. In the context of offline engineering, the programmer of the safety application is responsible for the verification and validation of the safety application. It must be assumed that errors may occur during the transfer of the information model from one engineering system to another.

As a consequence, all type values described in this clause are defined as read-only, i.e., they can not be written by general OPC UA write commands.

6.1 Object and ObjectType Definitions ToC Previous Next

6.1.4 Method ReadSafetyDiagnostics ToC Previous Next

This method is mandatory for the profile SafetyProviderServerMapper and optional for the profile SafetyProviderPubSubMapper (see It is provided for each SafetyProvider serving as a diagnostic interface, see Clause 9.2.


ReadSafetyDiagnostics (
[out]	UInt32	InSafetyConsumerID 	[out]	UInt32	InMonitoringNumber
[out]	InFlagsType	InFlags
[out]	Structure	OutSafetyData
[out]	OutFlagsType	OutFlags
[out]	UInt32	OutSPDU_ID_1
[out]	UInt32	OutSPDU_ID_2
[out]	UInt32	OutSPDU_ID_3
[out]	UInt32	OutSafetyConsumerID
[out]	UInt32	OutMonitoringNumber
[out]	UInt32	OutCRC
[out]	Structure	OutNonSafetyData)

Table 10 – ReadSafetyDiagnostics Method Arguments

Argument Description
InSafetyConsumerID see Table 8
InMonitoringNumber see Table 8
InFlags see Table 8
OutSafetyData see Table 8
OutFlags see Table 8
OutSPDU_ID_1 see Table 8
OutSPDU_ID_2 see Table 8
OutSPDU_ID_3 see Table 8
OutSafetyConsumerID see Table 8
OutMonitoringNumber see Table 8
OutCRC see Table 8
OutNonSafetyData see Table 8

Table 11 – ReadSafetyDiagnostics Method AddressSpace definition

Attribute Value
BrowseName ReadSafetyDiagnostics
References NodeClass BrowseName DataType TypeDefinition ModellingRule
HasProperty Variable OutputArguments Argument[] PropertyType Mandatory
Conformance Units          

[RQ6.7] Instances of SafetyProviderType shall use non-abstract DataTypes for the arguments OutSafetyData and OutNonSafetyData.

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