8.2.3
Description of OPC UA Server
8.2.3.1
Data model
The SIG350 has an OPC UA interface. OPC UA is a platform-independent standard with
a service-oriented architecture for communication in and with industrial automation
systems.
The SIG350 module provides an OPC UA server at field device level, to which an OPC UA
client can connect to exchange information.
The OPC UA device model is based on the general device specification:
OPC 10000-100: OPC Unified Architecture
Part 100: Devices
Release 1.03.1
2021-12-07
https://reference.opcfoundation.org/DI/docs/
In addition, the IO-Link Companion specification is implemented with the exception that
all functionality related to the IODD is not supported by the SIG350.
OPC 30120: OPC Unified Architecture for IO-Link
IO-Link: OPC Unified Architecture
Release 1.0
2018-12-01
https://reference.opcfoundation.org/IOLink/docs/
Basically, device access in OPC UA is done via objects and thus follow an object-ori‐
ented approach. Parts of an object can be
variables
,
methods
or
events
. The structure
and content of objects are each described by corresponding data types, which are
defined either specific to profiles or devices. Objects can be derived from several
base classes and inherit the corresponding properties in the form of
attributes
and
references
.
•
Attributes
provide information about the object and essentially enable access to
the payload.
•
References
describe the hierarchical arrangement of the object in the device
model and the relationship to other objects.
All object data types are derived from the UANode base class and thus have properties
(attributes) that enable access in the OPC UA address space via “nodes”. For example,
the “NodeId” attribute can be used to access the instance of individual objects, since
this allows them to be uniquely identified,
see "Access to process data", page 54
.
More information and a detailed, comprehensive description of OPC UA can be found at
https://reference.opcfoundation.org/
.
OPERATION
8
8027836./2022-06-10 | SICK
O P E R A T I N G I N S T R U C T I O N S | Sensor Integration Gateway - SIG350
47
Subject to change without notice