What is BS EN IEC 62541‑8 about?
BS EN IEC 62541‑8 is part eight of the overall OPC Unified Architecture (OPC UA) standard series
and defines the information model associated with Data Access (DA). BS EN IEC 62541‑8 particularly includes additional VariableTypes and complementary descriptions of the NodeClasses and Attributes needed for Data Access, additional Properties, and other information and behaviour.
The complete address space model, including all NodeClasses and Attributes is specified in
IEC 62541-3. The services to detect and access data are specified in IEC 62541-4.
Who is BS EN IEC 62541‑8 for?
BS EN IEC 62541‑8 on OPC Unified Architecture is useful for:
- OPC Foundation members
- Web services providers
- Cloud service providers
- Discrete manufacturing industries
- Process manufacturing industries
Why should you use BS EN IEC 62541‑8?
Data Access deals with the representation and use of automation data in servers.
Automation data can be located inside the server or on I/O cards directly connected to the server. It can also be located in sub-servers or on other devices such as controllers and
input/output modules, connected by serial links via field buses or other communication links.
OPC UA Data Access Servers provide one or more OPC UA Data Access Clients with transparent access to their automation data. BS EN IEC 62541‑8 defines the information model associated with Data Access.
BS EN IEC 62541‑8 specifies the services needed for the purpose of data access.
BS EN IEC 62541‑8 defines additional codes and rules that apply to the StatusCode when used for data access values.
BS EN IEC 62541‑8 provides details on mapping OPC COM Data Access (DA) information to OPC UA to help you migrate to OPC UA based systems while still being able to access information from existing OPC COM DA systems.
What’s changed since the last update?
BS EN IEC 62541‑8:2020 is the third edition that replaces the second edition published in 2015. BS EN IEC 62541‑8:2020 edition constitutes a technical revision.
BS EN IEC 62541‑8:2020 includes the following significant technical changes with respect to the previous edition:
- Added new variabletypes for analogitems
- Added an Annex that specifies a recommended mapping of OPC UA Dataccess to OPC
- COM dataaccess
- Changed the ambiguous description of "Bad_notconnected"
- Updated description for EUInformation to refer to latest revision of UNCEFACT units
