Transfer Object

The following overview lists the available transfer objects for the OPC client and shows at a glance whether they are supported by OPC Classic and/or OPC UA.

Transfer Object	OPC Classic	OPC UA	Description
OPC Data Access	✅	✅	Read or write one or more current values on the OPC server.
OPC Dynamic Read	✅	✅	Reads dynamic items passed at runtime via the configured OPC connection and returns the read dynamic values as a list.
OPC Dynamic Write	✅	✅	Writes dynamic values passed at runtime to the OPC paths of the configured OPC connection, which are also passed at runtime.
OPC Structures	–	✅	Enables reading and writing complex data types (structures and structure arrays) from an OPC UA server. Example: Current job defined as a structure in the PLC.
OPC Message	✅	✅	Secure transmission of OPC telegrams via change counters with an optionally configurable response telegram.
OPC Methods	–	✅	Call OPC UA methods on the target OPC server. In OPC UA, methods provide both input and return parameters. Example: Euromap 77 includes a method for starting a job. This allows the machine to execute various logic within the call and return the result.
Multiple OPC Read	–	✅	Dynamically read changes under a selected OPC node. You can set filters for desired and undesired elements.
OPC Batch Read	–	✅	The OPC Batch Read transfer object simplifies reading multiple OPC values with a uniform structure without having to specify each value individually. Example: Reading lists of jobs with their properties. The job structure and list length need to be defined only once.
OPC HA Read	–	✅	“OPC HA Read” reads data from an OPC UA Historian or OPC UA HA server and provides historical value trends or aggregated values for further use in OPC Router.

Notes

• ✅ = supported
• – = not supported
• Transfer objects such as methods, structures, Batch Read, Historical Access, and dynamic node reading are only available with OPC UA.