Connectivity Framework Annex B: Assessment Template: OPC-UA
B. 6.5 Implementation Viewpoint B. 6.5.4 Scalability Considerations
Data Objects( Section 4.2.4.1)
Apps( Section 4.2.4.2)
B. 6.5.5 Availability Considerations
Redundancy( Section 4.2.5.1)
Recovery( Section 4.2.5.2)
B. 6.5.6 Deployment Considerations
Platforms Constraints( Section 4.2.6.1)
Incremental Upgrades( Section 4.2.6.2)
Can the connectivity framework effectively handle an increasing number of data objects? What limits data object size?
Yes, OPC-UA can effectively handle an increasing number of data objects. In OPC-UA, the number of data objects on a server would be limited by the memory on the server and the average size of the data objects in that ' s server. There is no upper limit on the size of a request or reply.
Scalability for a server( with respect to the number of clients) is limited by the number of TCP connections it can sustain as well as the number of independent monitor streams it can produce.
Can the connectivity framework effectively support interface evolution for an increasing number of distributed application components?
OPC-UA protocol can easily be extended with new services and data types in a backward compatible manner. OPC-UA is a carefully thought out set of services that address the needs of device integration. Unlike approaches( such as SOAP, REST) where each application defines a new service API for specific purposes, resulting in an explosion of services, the advantage of OPC-UA is that once an application supports the service set it needs, it can interface with any device or system.
Can the connectivity framework support continuous availability over a defined systemrelevant time period?
OPC-UA defines several redundancy features that allow seamless client and server failovers. For example, subscriptions defined with a server can be transferred to a redundant server without the need of the application to recreate a new subscription. Can the connectivity framework support recovery when fault conditions occur?
The ability to support redundancy and then monitor the current operating state are defined in the standard, and applications can discover these abilities.
Does the connectivity framework support the operating system( OS), the CPU and the resource constraints on the platform( s) being used?
OPC-UA implementations are available for a variety of operating systems, CPUs and resource constraints. Does the connectivity framework facilitate incremental upgrades?
Yes, OPC-UA supports incremental upgrades by allowing OPC-UA Servers to be updated independently of the Clients when a device is upgraded. A server can be upgraded while a redundant server provides continuous support to its clients with no downtime.
IIC: PUB: G5: V1.0: PB: 20170228- 80-